You can do it at the below site. Costs $325 and I think this is good for 10 years. Takes at least 6 months. I filed in March and I'm still waiting for it to be processed. http://www.uspto.gov/
Yes I did mine myself. It was very easy to do. All the info you need is on their website. You can look at some other electrical companies trademarks on the site to get some ideas for information to put on the forms. Like Pat said you can also register with your state. The fee for my state is $20.