Startup Journal
At the Startupjournal.com you can do a trademark search for Federal trademarks and Canadian trademarks and a domain name search at the same time. The two searches should go hand in hand before you ever name your business OR choose a domain name.
Choosing a domain name or naming your business before you do either can be costly in the long run if you find out you the have the domain name of someone who owns that trademark. The US courts are awarding up to 100,000 per trademark infringement! Do your homework.
You can visit this business resource here:
http://www.startupjournal.com/partners/tmsearch.html
