Here is a list of four autosubmitters that could easy your work when thinking about social bookmarking websites' submission. Be adviced, do not use more than 1 tool or your content submitted could be taken as spam as it would be submitted more than once on the same social bookmarking site:

1. Social Marker - with this tool, your link will be widely spread on 48 sites in several minutes

2. SocialSubmit - it contains a list of 45 bookmarking websites

3. Onlywire - this contains fewer solutions for webmasters; you can also use a "sharing" button for WP blogs

4. Social Poster - this contains a bigger list, more exactly 160 websites; they also provide some other interesting SEO tools for bloggers, check them out on their webpage