A Division by Zer0 put together a nice, succinct compilation of resources that may help atheist bloggers trying to get their names (or pseudonyms) out there. Many of the items are useful for all bloggers, but a few are specific to atheists.
vjack has also been offering a series of comprehensive tips that may help those bloggers who have a *bit* of experience. His tips work for all bloggers in general.
If you’re just starting your blog, check those sites out. I can personally vouch that a good number of the resources they discuss are fantastic and I use them frequently.