Jump in, it's fun.

My first was out of dish and had a couple of flat spots. Was nice and true though!

It is fun. You won't build perfect the first time, probably not the second or third, this is something that just takes practice. It is fun and satisfying when you finish a wheel though, even if it isn't perfect. You'll learn from your mistakes and the next wheel will be better. You will eventually be able to build good reliable wheels but you can only do that if you take the plunge and just do it.