What sort of backlinks do you want? * Article directory submission? * Directory submissions? * Social Book Marking? * Blog Commenting? * Profile creation? There are a lot of different aspects - would help if you were a tad more specific!
The best link building tool is the one between your two ears ;-) Seriously now, before we can help you we need do know a bit more! SY
You can use back link software, article submissions, link exchanges, manual exchanges with other webmasters, blog commenting and etc. You should mix and match when you build backlinks. Higher authority sites carry more weight. Social networking sites such as FB and twitter help your site too. For a start you can try out my back link generator for free. Hope it helps. PM me if you need any help.