Ask HN: Big clients, now what?

The past weekend one of the startups I am involved with (I own a decent chunk of equity and am employee numero uno) got their first handful of major clients. Two are fortune 500 companies who are very excited about the product and are prepared to spend big money. Everything is still under wraps but we are starting to discuss our next move. We are technically profitable and do not necessarily need funding. Yet, a round would surely help us grow quickly. Honestly, we are a group of kids who love to code and didn't figure everything would happen so fast. I am sure this has been answered here before but I would love any advice on how to approach VC firms or apply for grants without losing control of the project we love. Thanks so much :)