[G] Beginner's guide

So, you want to play StarCraft II online! Be aware that SC2 is very competitive, and multiple degrees of freedom operating within its structure that make it fairly complicated for new players to learn. But life isn’t interesting without challenges, right? The most important thing to realize about this idea is that the power differential between one level of play and the next can be very high; the very best players can appear as miracle-workers or even cheaters to the lowest-level players. Don’t let this discourage you! You play games to have fun, so always remember to have fun, and the more you play, the more you’ll learn – or want to learn, at any rate.

If you’ve played the campaign, you know that the goal is to make units and go kill the enemy. The problem with multiplayer is that both players are doing the same thing – so the game becomes a question of how do you make better units to kill your enemy better?

Here’s what traditional SC2 pedagogy will tell you: Macro, macro, macro. This is the core of SC2 gameplay, and the main way you’ll improve. What is macro? It stands for macromanagement, as opposed to “micro” or micromanagement, and to paraphrase one of the in-game tips, if you “use your resources as much as you can, you can make a larger army than your opponent. The larger army usually wins.” I hold that macro is largely a method in economic thinking and being as economical, or cost-efficient, as possible. We’ll start with the first “rule of StarCraft” to illustrate why:
Rule #1. Keep your resources low.
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Investments and rule #2-3: ALWAYS remember that you need to make more workers!
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After economy comes the rest of your investments; rule #4
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One important note; rule #5:
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Shift+clicking is useful in many ways, but it is best to figure them out for yourself. However, one very helpful way of spending attention well is to use hotkeys and control groups, terms which are sometimes confused, as hotkeys may refer to control groups as well in most communities.
Hotkeys are, strictly speaking, buttons you can press to issue a command instead of clicking the command card. For instance, if you want a probe to build a pylon, you can select it and press BE then left click the building placement rather than clicking Build, the Pylon icon, and then clicking the building placement.
Control groups allow you to store and recall unit selections. For example, selecting your army and then pressing Ctrl+1 will allow you to select your army from anywhere on the map by pressing 1. Set-ups will generally put army on one or more (up to around 4) hotkeys, production buildings on one or more others, and townhalls (Nexus, Command Center, Hatchery, or derivatives) on one or more others. When you have a unit or units selected, use Ctrl+# to set the control group and Shift+# to add to the control group.
Note that double-clicking a unit or Ctrl+left-clicking a unit will select all units of its type on the screen, including buildings! This is useful for selecting and producing off of a set of buildings, one set of units at a time. For Protoss after Warpgate research completes, this is automatic with W; keeping all your warpgates on a hotkey is then optional.
Here’s a way to use control groups to follow Rules #1, #2, #3 and #4 (based on my personal set-up): Hotkey your Nexus on 5. No matter what point in the game is, obsessively tap 5 and see if 1 worker is building. If not, then press E. For multiple bases, tap E multiple times, and if accidentally queued too many (and thus leaving me no resources for army), press Esc a few times.
Hotkey your gateways/barracks/etc. on 4. After checking 5, tap 4 and do the same thing, but with army instead of workers.
If after checking 5 and 4 and seeing that all my buildings are working on 1 thing, and I see I still have resources to spend, I invest in more tech, more production (barracks or gateways etc.) or an expansion (riskier).
If I have no resources and no buildings are idle, I poke around a bit with my army and see if I can beat my opponent. If not, I keep on “macroing” until I can.

The control group method listed above, where one mostly just makes workers and units as efficiently as possible, is a simplified explanation of how one tries to win a “macro” style game. Obviously, there is a huge variety in what kind of tech to invest in and when to expand, and at higher levels one sometimes wants to cut workers and/or cut army to hit certain timings, but that is an overall “standard” way to play. In standard StarCraft pedagogy, the other two ways are added on as you go, attached to a macro foundation. I think that learning all three is important, and you can do them in whatever order you feel like, and mix and match as you please. But the other two ways, as I see it, are:
Rush/cheese tactics such as 6pool, cannon rush, proxy 2gate, proxy 2rax. These aim to put on very early pressure and can do terrible terrible damage if unscouted, or if your opponent is caught off-guard/doesn’t know how to defend properly. Many parts of the community look down upon cheese as dishonorable or cheap tactics, but they are occasionally used by professional gamers in certain specific contexts.
Micro/army composition victory depends on knowing unit counters and the like to give you a strategic advantage. Unfortunately, if you don’t have baseline abilities with macro, you can’t use these to your advantage well enough. For example, marines are generally a good strong unit, because they are small and ranged and have a short attack animation, which means you can keep on adding more of them for damage while keeping them mobile. However, they are weak to “area of effect” (AoE) damage such as psionic storm, banelings, or siege tank fire. However if you don’t have enough AoE units, more marines will still kill you, even with perfect control. This is why traditional SC2 pedagogy focuses on macro for winning games, and not army composition; as one player puts it, “you can pretty much play purely marine/marauder, blink stalker, or ling/baneling all the way into high masters. Mechanics [macro] are what matters.”
Scouting and map control play an important role in all three “styles.” In the macro style, you can tell when to engage and when to expand (a rock-paper-scissors analogy of attack>expand>defend> is useful here). When seeking a unit composition victory, it obviously helps to know what kind of army your enemy has so that you can make the proper counters. How do you scout? In the macro style, it is often as simple as holding the Xel-Naga Watchtowers with a single unit. Otherwise, there are a variety of race-specific ways. Protoss observers, Protoss hallucinated phoenix, Zerg overlords, and Terran scans are but some of the ways to perform scouting. “Tech” often corresponds to “expand” in the rock-paper-scissors analogy briefly given above, meaning, for example, if your opponent takes lots of gas geysers, you want to attack him early before he can get good tech, or expand/tech up yourself.
All three styles become important as you become better at the game. The majority of professional games are a complete combination of macro and micro styles, where each player is macroing as hard as he can, microing as hard as possible in major engagements, and scouting to find the best unit compositions to deal with the enemy, as well as positioning army and buildings in the most strategic positions, which I would classify under the micro style.

After reading this guide, where do you go now? http://wiki.teamliquid.net/starcraft2/Main_Page <- Liquipedia is a great resource for reading and finding build orders to follow and practice. Build orders can instruct you on some specific sequences of balancing your investments in production, army, tech, etc. which put you in a good strategic position. Liquipedia also has general strategy tips, some of which overlap with this guide, some of which cover specifics of strategic things like terrain and “the defender’s advantage.”
Blizzard’s “training feature,” in Matchmaking -> Training -> Stage 3 is actually more helpful than you may think. As long as you’re hitting the objectives they give you as fast as possible, you’re macroing up at a good speed and you should be able to defeat many lower level players if you play as though you’re playing Training Stage 3. In my experience, however, the one flaw of training is that it does not guide you through racial macro-mechanic (chrono, inject larvae, MULEs), so just remember to make use of that as much as possible as well.
Check out http://www.teamliquid.net/forum/viewmessage.php?topic_id=330787 for FilterSC’s “Bronze to Masters” guides, or http://www.teamliquid.net/forum/viewmessage.php?topic_id=330787 for JaKaTaK’s TheStaircase method, if you like watching videos and a structured way of improving.
For a slightly more casual way of improving, you can watch HuskyStarcraft commentaries or Day9 Dailies. This is more fun, and may not lead to improvement as fast as practicing, but it can give you a few insights here and there that you may not realize on your own. http://www.youtube.com/user/HuskyStarcraft and http://www.youtube.com/user/day9tv ; the community generally agrees Day9 is more useful for improvement and Husky is more entertainment-oriented.
If you like working one-on-one with volunteers – even pros benefit from coaching – you can check out the player-initiated “Adobt-a-newb” initiative; the forum post describing it is at http://us.battle.net/sc2/en/forum/topic/7592800176.
http://drop.sc/ is an excellent site for uploading replays, which can be found under My Documents/StarCraft II/Accounts/numbers/numbers/Replays/Multiplayer (the numbers differ for each player), and then posting on websites such as the Battle.net general forums, or Team Liquid forums, for seeking advice.
You can also watch your own replays to see what you did wrong. Maybe you accidentally cut workers here, or army there, or you engaged when his army was clearly bigger, or you were floating (not using) 3000 minerals there.

These options will generally improve your gameplay over time by providing more information to your UI:
Options -> Gameplay
Show Game Timer
Show Flyer Helper: Always
Show Health Bars: Always
Select Enemy Units
(uncheck) Select All Larvae
(uncheck) Simple Command Card

Make only probes until 9/10 supply
Place pylon at 9/10 supply as soon as you hit 100 minerals
(build probe for 10/10, queue for 11th probe)
Chronoboost nexus as soon as pylon finishes (at 11/18)
Keep making probes
At 12/18 when chronoboost wears off, chronoboost again
At 13/18 place gateway
At 15/18 place assimilator
Chronoboost the nexus as soon as you have 25 energy
At 16/18 place pylon