Every new player should check these out http://wiki.teamliquid.net/starcraft/Day(9)_Podcasts specifically the MECH Series, General Game Theory Series, and Hallmarks of Expert Play Series. Although these discuss SC:BW, they still provide the essentials of SC knowhow that remain present in SC2.
Another things that new players need to do is watch VODs, Replays, and Streams. Seriously, if you watch tons of SC2, then your game sense and understanding of game dynamics will improve significantly. When I watch progamers play, I constantly ask myself, "Why did he do that?" even for the tiniest things. I do this because I find that the overarching game plans and details of their build that high level players do are easier to copy if I identify them explicitly and give them thought.
After all this observation, you should just go ladder! Relax about losing and just realize that when you get better, you will know it because you'll be winning 80% to 90% your games and you WILL be promoted.