Hmmm... Always this is the first question which comes from clients or anyone who submits or plan to submit to the directory I usually recommend my clients or any one to go to :- DMOZ Look out for various categories which they think fits best to them as they have made their website. I understand we are SEO and we know better but then I argue that there might be some NICHE which is not in your case which not all of us are aware of say example some curry ingredients or spices sold out which you have never used then you may not know it well but person WHO has created the Website knows it well Yes yours and mine or SEO's knowledge will be based on research from internet if we have never used that curry or spices. So best person will be one who really developed website can tell more about it So ask them and make sure they give atleast minimum 2 choice or maximum 4 choices if possible from DMOZ list of categories . And then you with your research can compliment and help them find Best I always and always prefer DMOZ as it is BEST Directory and maximum categories then anyone else then based on clients input and your research you can submit to one of the 2 or 3 or 4 choice you agreed upon as it wont be necessary that all directories will have that category but some chances to match out of 4 options given.