There are some great sites out there that help you understand how to work with VCs, the top 3 in my book are the following:
The Funded– Great resource when researching VCs. You can search based on funding level, geography, how quickly they fund and also on how they are rated by entrepreneurs. Reading the comments left by other entrepreneurs is fascinating and full of tips, they’ll tell you which partners to approach and who to avoid.
Venture Hacks – From getting an introduction and making your first pitch, to term sheet negotiations, this site gives you step-by-step instructions.