You can find all sorts of nuggets of wisdom on the many Starcraft 2 Forums available. There is a huge variety of information and discussion going on from all skill levels. Just be careful not to get too caught up in the ‘TheoryCraft’! ^_^
The Team Liquid forums are the biggest meeting ground for english speaking Starcraft 2 (and Starcraft 1) players on the internet. Every detail of the game has been or will be discussed on these forums at some point in time. You will also find a variety of other resources here such as live streams, links to videos and blogs, custom maps and other tools. You can also find the Official Daytv Thread on the TL forums.
Find your local official Starcraft 2 forum and discuss the game with people in your region. The Battle Net forums are also a good way to find people in your region to have practice games with.
Do you know of any other good Starcraft 2 forums? If so contact me and let me know so I can put it up!