I had similar concerns when I started out with my new W7 Pro 64bit PC.
I found that W7 went online and found new drivers for my Epson Stylus 740 Colour printer when it was plugged in and turned on; similarly for the Epson V500 Photo scanner.
As for XP software, such as MS Word/Works suite, they operated under W7 (see my thread) but others needed installing on the virtual machine - very little failed to run.
As for transferring files and other information, I ran this thread which produced a lot of help from others on this site.
Hope this all helps.