Migrating to the Mac: moving my files

The move of my files from my Windows machine went more smoothly than I expected. I have a router at home connected to the iMac and my old PC and turning on the file-sharing on the Windows machine and clicking a few settings on the iMac let me access the files on the PC. Very convenient. Most of these files are pictures (jpegs), videos, mp3s and Word documents, files that can easily be accessed on a Mac so I anticipate no big problems ahead. Now I need an good FTP program. Any suggestions?