For screenshots check out the list of interfaces at:
Or just google around for "linux kde screenshots", "linux gnome screenshots", etc.
And just so you know, 64 bit distros normally aren't worth the trouble. They provide little benefit for the number of app / library hassles you'll encounter. imho, even Windows isn't worth the jump to 64 bit yet. It isn't like you'll see a huge speed decrease if you go the 32 bit route, in fact I doubt you'd notice a difference.
As for precautions, I don't know if you are dual booting or not, but a lot of people complain when lilo / grub override their boot partition. It's easy to fix once you understand more, but initially it can seem like your Windows partition was "destroyed". If you aren't dual booting, no problem then.