ConGermanicRomanceLang?

Hey guys.

I've had a blinding flash of inspiration lately: Why don't I make a
Germanic RomanceLang?

So, I've decided to roll with it.

Problem is, I know *nothing* about Latin or Germanic Sound Changes.
However, I do have friends who know Latin, and until I can get my hands
on some Latin, and Vulgar Latin in particular, info, I'll use them for
advice.

But the biggest problem is the Germanic Sound Changes - I don't know the
first thing about them.

Can anyone point me towards some (preferably free) information about the
sound changes in Germanic languages?