First thing I'd like to point out is the official errata. This document contains the most recent updates, as well as all of the past ones in one convenient PDF. No need to look through all of this, but as you're making your character you might want to check to see if any class features/powers/etc. that you chose have been changed (the doc is organized by book).
Second, if you have some free time on your hands and enjoy reading about such things, the Character Optimization Guides on the WotC forums are a pretty good resource. A lot of the specific builds are built around Epic tier concepts, but the individual class guides give a great overview of your options and really help to narrow things down now that there's a huge amount of feats and powers to choose from.