you developed a directory and you wanna develop it again? or u mean u want to promote it? if you are thinking about promoting, there is a directory category where yuo can announce your directory. thats a good start. and see what other directory owners do in that category. that will keep you going for a while
Go list it at: http://www.directorycritic.com If it's free, announce it in the forums at: http://info.vilesilencer.com and let me know, and I'll add it to my list. Doing the above should get you about 1000 submissions in a short period of time...
I think you can try to submit your directory to say http://www.addurl.nu etc. Also the main search engines like Msn, Google and Yahoo