Are you using an integrated Wireless card or Wired Networking adapter, it will most likely work as soon as you install.
As for files, back them up or create a new FAT 32 Partition of your HDD and you May be able to access it. (Not a guarantee...)
Go for Linux, I personally don't like Ubuntu, but it is good to try before you go into a better distro...
Dual boot, so if you can't access the files, you can change back to windows.
Wubi is a good tool to try ubuntu without a full install, and is full featured.
Wubi can also uninstall Ubuntu in a few clicks if you don't like it and you don't even have to partition hard drive.