you don't have to move over permanently... make it a dualboot and play with linux..
it's pretty interesting..
and it's really easy to make a proper dualboot too.. all the newer distros have that option under install....
but, feel free to back up everything first time you install linux..

most of your docs and excelfiles would open in linux... you can make your DOS programs work in linux too... you have to use Wine or some "emulator" of that kind... if you don't know what Wine is, Google it..