If all your data files are stored in libraries (My Pictures, My Videos, My Music, Downloads) then it will get them automatically, however if you have any folders that you created yourself like C:\savegames then be sure to hit the advanced option and select the extra data folders you wish to bring along.
Windows Easy Transfer only gets your user settings and data so you will need your programs and any respective product keys to install. It's also a good idea to download the W7 drivers for your specific computer and chosen bit-size (32-bit drivers are usually different from 64-bit).
And before you actually go to W7 it is a good idea to turn on all your hardware and run the
Windows 7 Upgrade Advisor on your current system to see if you will have any known hardware or software issues.