I'm not sure if you're anything like me, but I have always found Trademarks to be a giant mystery.  I was never sure if you should do it when immediately starting your business, or if you should wait when it hit a certain threshold.  I also once tried to do the Trademarking process on my own, and well, overwhelmed, is a complete understatement.  Tamsen Horton of Vuja De Law came to for a visit again to break down trademarks, and she gave us some great information.