Alot of people say you should not put your link in directories as google and others etc, now frown upon their use, because people have abused the heck out of them. So what is the real deal? Should we use Directory services, or run away from them? I was about to run my own Directory for my users, but after reading a few items, I removed it, as I did not want banned from google.
Refer to the google webmaster guidelines See where it says "Submit your site to relevant directories such as the Open Directory Project and Yahoo!, as well as to other industry-specific expert sites." I think you will be just fine submitting to directories and providing one on your site - just keep it well maintained to be a quality resource for your visitors.
I think what google really frowns on is the link farm type entities that masquerade as directories. There are still several great general and niche' directories out there that offer not only a good link but actual traffic as a result. I've seen no slowing down in the number of people listing in our two most popular directories, and I have not seen any legitimate signs that people are being penalized for doing so. Its fairly easy to distinguish the directories that accept any and all links, vs those that actually review and qualify sites as they are listed. YMMV