I just plug all my computers into my ethernet switch, and connect my Mac to my windows computer using the network. Just be sure to enable sharing on whatever folders you need to transfer data.

You'll find that files will transfer fine between Office for Windows and Office for OSX. There may even be an import filter built into Entourage to migrate your email over from windows.

Here's a handy resource among many on the web: http://www.macwindows.com/