If you log in to the site, you'll be prompted with a link to re-send the activation email. Make sure you check your spam, junk, and trash folders. If you're using a Microsoft email provider (hotmail, outlook, live, etc), you should follow these instructions:
1) Sign in to the Windows Live Hotmail website.
2) In the upper-right corner of the page, click "Options", and then click "More "Options".
3) Under Junk e-mail, click "Safe and Blocked Senders".
4) Click "Safe Senders".
5) Enter tradeskillmaster.com and then click "add to list".