Search Engine Optimization is almost a myth. The most that you can do is make a site that people are willing to visit on a weekly if not daily basis. That has to do with content. As far as DMOZ is concerned, they take a long time to add your site because they are picky about who they add to their engine. That is why their engine is one of the best out there. Yahoo Directory charges an arm and a leg to submit. Overall be concerned with your content more than anything, the bots will come.