Visitors often like to "meet" the person behind a blog--don't make it too difficult for them. Some basic information about you (including contact information) should be just one click away from your main page. It also shouldn't be too hard to find. If you use wordpress, you can create a "static page" with your contact information.
Blogspot makes this pretty easy--there's an "about me" widget that is often automatically linked to your new blog. But there are other options. You can great a blog post with your information, or even a separate page (like a free google page).
Here's another suggestion: you may want to put your email address on a picture file like this:
This will keep the spam bots from finding it but makes it easy for people to see it.