O.K. Let's say you've got you're site up, done, looking good and you feel you are ready for visitors... How do you go about that? Here's some stuff I've found along the way that may help.
My biggest piece of advice here is to be careful. If it feels like you are doing something just for the search engines, rethink it a bit. Also be cautious who you link to (linking to bad neighbors can get you in heaps of troubles) and try not to panic if at first your site receives few visitors. Just try to make it the best you can, and eventually the traffic will more than likely start flowing in. There's no good quick fixes, but the links below are a great starting point.
Webmaster World
This is one of the busiest forums I've found that talks about anything from building your site to promoting it.. with a heavy leaning towards the promotional side. Well worth browsing (or studying) to find out what can effect your rankings in search engines, what the big boys of search are looking for and to find lots of other ways to advertise your website.
Virtual Promote
Before you begin any promotion for your site, go here to find out what will help and what could ruin your chances for a well ranking site. This is a huge place that offers free promotion tutorials, lists of where to submit your URL, and a lot more!
Most search engines will give you an idea of how many web sites link back to you and who they are. For example visit Google and type link:yourdomain.com to get a small sampling of your inbound links. For more detail I'd recommend Yahoo Site Explorer, this tool gives you much more detailed information. These will, however, only tell you about sites that are registered in those search engines, so you might be more popular than they say but it should give you an idea.
If you are looking for places to add your site, Site Explorer is very handy to, just look up what similar site as yours are doing and you're set to go!