Remote connection via different network

Hi guys,

I'm running two windows 7 PCs, and I'm always on my college's campus. There are a great many times that I'd like to be able to access my computer at home with my small laptop while on the college's internet. I don't know that much about remote desktop access, but from what I understand, you can only access a computer with Microsoft's build in app if you're on the same network. Or is this just false? If this is indeed the case, what can I do so that I may remotely access my home computer, regardless of what network I am on? (If that's really even possible. Like I said, I know nothing about remote access).

Thanks in advance for any advice and/or help!

Here's one link and another

Google for Remote Desktop (don't hit enter immediately) and it even suggests Remote Desktop for Mac