My favorite word of the year: Dropbox! Go to Dropbox.com, download the software on both computers. Create an account from one of the computers, and then sign into that same account on the other computer. Anything you put in the folder called Dropbox that's now in your home folder on your Mac (or in My Documents on a PC), will appear in your Dropbox on alllllll your other computers — and iPhones, and iPads, or Android phones, and pretty much anything that can see m.dropbox.com. 

For what it's worth, there are other services like Dropbox out there, including but not limited to SugarSync and Box.net, but through sheer simplicity and elegance, Dropbox has so far garnered most of the love. The iPad app is off. The. Hook.