There are literally a lot of social bookmarking softwares out there .. you can choose to get the best ones ..

I have some services that i use for social bookmarking ..
Its TrafficGeyser.com .. it is the best and has a lot of potential ..

And SocialMonkee.com .. you can generate easily 30 Backlinks a day from this service for Free and around 100 backlinks a day in the premium upgrade .. its kinda cheap too ..

I hope i helped.