Hey, I just started up a directory a few days ago (in sig), and I was looking for the best ways to promote/advertise it for free. I'm posting on forums, and submitting to directories. Any other useful tips? Thanks.
Talk to your online acquaintances and see if any of them would be willing to write a blog post about your directory with at least one link back to your site.
writing articles about directories and then posting the article in places like ezinearticles, goarticles, articlecity and isnare have worked good for me - they allow you to have a bio with a link to your site you can also do free press releases...
Go to info.vilesilencer.com, there is a directory list, register and send to their forums, if you are lucky, you will be listed in the next update and it send 1500 uniques everyday. Try finding other lists like that one, there are a few and try to get listed. Writing articles or PR will be no use for a web directory, i believe...