PaulinMaryland said:
The filesystem doesn't matter in that context. It's basically a folder of sorts (not exactly, but it's close enough) that exists as a shared "place" for the computers on the network. Yes, Windows can read, and write, to that, and Mac OS X can read and write to it as well.
Here's a great guide right here on MR Guides that shows you exactly how to do it. (This guide assumes that you don't have Bonjour, so ignore the IP address, Bonjour simplifies it to a simple "(your computer's name).local. That's it. You can find what you need in the Sharing prefpane in System Preferences): Networking Windows with Mac OS X