Scott,
I usually upgrade about every three years, which is probably about as much as my heart can stand. The best advice I have is to begin from scratch. Granted, it takes a bit longer, but it's usually the best route to take.
First and foremost, you eliminate all those junk programs that you rarely use. Next, you don't have to contend with all the leftover files from programs that have been uninstalled, reinstalled and just plain deleted. No viruses, worms, variants, none of those to worry about until you go back online and begin downloading files again.
As for the data transfer, I use a USB to USB transfer cable that is extremely fast, and only cost about $20 at
www.cyberguys.com . It comes with software that is installed in both computers and is very user friendly. Just drag and drop the data you wish to transfer. You'll find the cable at
Cyberguys Good luck on your project,
Gary