Adding new products

I installed Zen Cart, but forgot to select option to include the sample data.
How to add products correctly to Categories and Subcategories on a new Zen instalaltion without the sample data?
Should new Categories and Products to be created inside one of the 5 root Categories as Subcategories?

Product - General
Product - Music
Document - General
Document - Product
Product - Free Shipping

Those are Product Types, not categories.

You just go to Admin - Catalog - Categories/Products and start by clicking 'New Category' to start adding your categories, subcategories and products.

stevesh:

Those are Product Types, not categories.

You just go to Admin - Catalog - Categories/Products and start by clicking 'New Category' to start adding your categories, subcategories and products.

When fill out the information for the new category:

Category Image: is a must or optional?
Upload to directory: should be selected 'categories'(default) or Main Directory?(for example)

What mean "NOTE: Category has SubCategories. Products cannot be added"?

Also, when upload images, which directory better choose to upload: Main Directory, categories, etc?