Congratulations!!
I do agree with Kena. If you have any doubts, Google him.
I would also really have him outline the basis of the work and get it all in writing. Make sure to draw up your contract and have it signed!
Make sure you have good communication with him and throw a few more emails his way discussing projects, how you are going to receive them, timelines, etc...Just make sure you have everything in order and again...you get that contract signed before you begin any work!
Yeah for you!!!!