Apple Thoughts: Learn All About iTunes 10

"iTunes 10 is here, we've been using it for a while, and now we've got a complete walkthrough for iPhone, iPad, and iPod touch users. If you're new to iTunes 10, especially if you're new to iOS devices, we'll help you get up and running quickly."

A pretty complete yet simple run down of all the features in iTunes 10, and it's a quick read so you don't have to spend too much time studying and can get right to doing. One thing mentioned in the comments was an interesting tip. With the colored iOS capacity bars, they update immediately when you check or uncheck the sync option under the tabs for the device you are going to sync. This will certainly help you plan if your device storage is on the edge.