Submit your site and see if people like it, that's the gist of it. Make sure you pick the correct category or your results may suffer. You can also launch an
advertising campaign that is considered by some (depending on you niche) to be a great method of driving traffic to your site. Good luck.
By the way, I would not make a habit of submitting pages that you don't consider to be highly valuable as your Stumble account may quickly become powerless (fewer or no stumblers will see your pages). Only submit pages that rock, either your own or others, just don't submit junk.