Builds are a lot of fun, I've been building a 650 for the last few months. Gone a bit overboard on it, but when it's done it will look pretty good. Be sure to take pics and post your build on the project forum, we all love following those.
I think Twotired owns a lot of the 550's, if you have any questions, you can post or even just PM him. Especially carb questions, the man has forgotten more than most of us will ever know. Just be sure to do a couple searches first as a lot of info has been posted. Also, you can look at Bikebandit for exploded diagrams if you don't have the manual or it doesn't have one. Sometimes that can be helpful.
Brandon