Here are profiles of my favourite social bookmarking sites.

Delicious

Del.icio.us is a social bookmarking site which allows you to record your bookmarks and share them with others. They also have a useful tool which allows you to post your bookmarks to your blog on a daily basis which is great for creating content without much effort.  Each entry is tagged and people will use the site to research popular websites in a given category.

I have found that submitting my pages to Delicious have produced some traffic for my blog but nothing spectacular.  However it is a very useful tool.

Here is my Delicious Profile 

Digg

Digg is a site which allow users to submit articles off the web which are then voted on by the digg community.  As you might imagine the more votes an article gets the more popular it becomes and really popular articles can generates so much traffic for the originating website that their servers fail.

I have found that submitting my pages to digg generated a spike in traffic for a day or so after submission.  Here is my digg profile

Stumbleupon

Stumbleupon is a lot like delicious, but with added social network functionality. Users can bookmark sites which will then be recommended to other users with similar tastes.  Similarly to Delicious, these stumbles can be posted to your blog

I found that submitting my pages to stumbleupon had a massive effect on my traffic. Here is my Stumbleupon profile

Getting people to submit your pages to social bookmarking sites 

The best way of getting people to submit your pages is to make it easy for them.  Plugins like Sociable (which I use see below) and Addthis, allows you to easily place submit buttons on your website or blog post.

Make Money by bookmarking 

A company called Subvert and Profit enables advertisers to pay for votes on Digg or Stumbleupon.  Probably not very ethical and will possibly get you banned.  Probably not worth it for the $0.50 per vote.