Vista is quite a bit different than Windows XP.. For instance, shutting the computer off. The keyboard shortcut does not work like it does with XP. YOu have to go the the round world on the lower left, Then click the arrow next to the lock to even see how to shut the computer off.
The Windows explorer is also very different. So be sure you poke around to become familiar with the way the files are displayed. Otherwise, when you need to find something, it is a challenge.
Also, don't be surprised if some of your older programs will not run on Vista. Quite normal. Many software programs have updates on their websites for the Vista. So be sure to check each software program after they are installed on the new computer.