When you are in the edit profile mode, you just copy your blog address and paste it into the editor at the appropriate place. You can also link a key phrase.
Example: Lets link (Life Insurance) If your blog is about life insurance it would be natural to link those phrases.
Type out your description:
My blog (Affordable Life Insurance) focuses on helping people save money and find better coverage for their families. Stop by Now and get a Free Quote at (http://affordable-life-insurance)
You could then actually link both the phrase (Affordable Life Insurance) and the web address as well.
Highlight the link button in the editor options, it looks like an 8 laying down, when the link box opens type in your blog address (I suggest copy and paste to make sure it is right) You can type in the alternate title of the link to show people what the link is about. Then save and the link is live.
This will allow you to link to any place that helps you build up your name, hop this made sense and helps.