hi ahb12000, I don't know how to do this in iTunes, but in the past I just signed up with Delicious and had bookmarks over there. Then just login on your iphone or ipad.
Other than that, I hate iTunes so can't help you with that :( But I think it involves exporting your Firefox bookmarks to Safari (You will have to install Safari on Windows 7) and then choose "Sync bookmarks with Safari" in iTunes.
How can i synic the Bookmarks between
Iphone 5.0.1
Ipad 4.3.3
Firefox on my Win7 PC