There are loads of social bookmarking sites. Search on the net for the most popular ones. The are not hard to find.
Try a service like http://www.socialmarker.com/ to submit to many of the top social bookmarking websites quickly. Be aware that social bookmarking only works well for certain types of websites. Many websites would get very little benefit from social bookmarks.
Don't spend too much time trying to get traffic from social bookmarking sites, yes you can get a nice number of visitors if your site gets picked up but have a look at what a typical action is at these sites. People will click out of curiosity, bounce rates are high, many just use bookmarking sites to get sites/pages indexed quickly. It differs depending on your market and what you are promoting but I have never got much of a benefit from the sites.
Here's my list of social bookmarking site http://myresources-cora.blogspot.com/2008/07/list-of-social-bookmarking-site.html
I recommend not to concentrate too much on social bookmarking sites to draw visitors because the quality of traffic is poor; try organic search engine traffic and build good contents. You will gain a lot
Most of Social bookmarking sites is not given the follow link so it's not benefit in SEO. please also try to add your website in directory,Article website,blog and comment posting.