Theres a lot of information that goes along with those simple questions.
Social Bookmark sites are sort of like directories other than they link to your posts and not your index page. I haven't played around with them much but I am thinking getting some links into my pages as opposed to my blog roll wouldn't be a bad thing. Just not sure which if any of the sites are worth it.
UW's LL
PerveSpace takes blog posts.
Pinging, you have a WP blog and haven't messed around in the options too much, happens automatically with WP pinging Ping-o-matic by default. Ping-o-matic, then in turn, reports to a number of feed directories that you have updated your blog.
If you haven't sumbitted to the feed directories, or at least the ones that take adult, the pinging will do little. Some will list you some won't. If you look around here and a few other places your bound to be able to find a long list of feed directories. Most of them wont take adult though.
Thats the short version....I think