The best thing to do with DMOZ is to submit once to the best possible category, do your best to write a guidelines-compliant title and description, and then go to work building more content and links to your site. A DMOZ listing won’t make or break your site.
Guidelines for Suggesting a Site to DMOZ
You might want to read both sets of guidelines above, as well as the description and guidelines for the category that you’re submitting to. Hope that helps.