StarCraft 2 is like chess but on steriods / tons of redbull.. You need a vision and a set of objectives in every game, I don't think you will get very far without a proper thought out strategy. Get to know the maps you like to play on and make sure to properly study them. I know this sounds boring but really it will make a difference. Once you know where to expand or where a cliff attack could happen you will have a lot more control over the map then before.
Check this guy out: http://day9tv.blip.tv/ (bliptv) http://www.youtube.com/user/day9tv (youtube)
Day9 is great at really breaking down SC2 maps and in game strategies, you will learn very many things from just listning.
I think Terrans and Protoss and quite balanced against each other, however I do think that Zerg is broken. I win most of the time against Zerg and I play either as T or P. Blizzard needs to review the Zerg race.
Well.. I sit back in my chair and ummm... have one hand down my... eeeehh .. No honestly, I listen to the podcast while I am working in the office. I'm mostly working with spread sheets so doing numbers while listening to the crew is pure bliss. :D