By far the easiest way to move stuff from your PC to the Mac is by having the two machines on a network together.
This involves the use of a Router/Switch, a switch or a hub. If you plan on keeping the PC and want to get on the internet with it, a Router would be the best route. That way both machines can surf at the same time. (assuming broadband connection here)
Failing that, a USB 2.0 hard drive would work (do not format it NTFS) or even a 1 or 2 GB thumb drive.
Bear in mind that you will not be transferring programs from the PC to the Mac, they will not run there. You will only be moving the data you have created. Office documents, Quicken, music, photo's, etc.