Ok will do Ray, I will try out your approach as I like the flexibility in case client wants to add products to many categories. As a starting point I just wanted to outline what I assume would be the logical way to setup...
1. Would I still still maintain extra category information (such as a category banner image, category description) in the category table? or would be be sensible to store that information in another table?
2.ADMIN - Currently when creating a new category I get the client to type a name of the category, in addition they have a drop down menu to where the sub-category is pointing to. Could I still keep this approach, but instead the drop down select list would continually include new categories that have been created in this admin page? (if the client doesn't select anything from this drop down then there will be a NULL value stored in the record) is there any potential problems with this approach?
What approach/steps would you have taken in creating this in the clients admin pages?