I have two blogs and I use every means I can to advertise them. One way is advertising in directories. Good source of backlinks and some traffic. I have a directory that is aimed only at blogs and forums. Nothing else is allowed into the directory. http://forums.digitalpoint.com/showthread.php?t=142028 And go up to the directories forum here and you can find some other good directories to advertise your blog.
Hmm wasn't sure we could advertise services outside of the "marketplace" when I read your title I thought you were looking for help to promote your blog.
On a related note, one way to promote your directory is to announce it in the directories forum. You may also get away with spamming other forums with thinly disguised advertising - just make it look like your providing useful information.