more database help.

Id greatly apperciate (like you guys have always helped when I needed it). heres my full content of ecommerce, Id like to make a search engine like amazon.com where there is a pull down menu, and you can search from particular catagories my catagories are : (and there are many subcatagories)

1) Wheels/Tires
brands - 20 or so
2) Exterior
- body kits
-wings
-headlights
-taillights
-etc.
3) Interior
racing seats

4) Suspension/Brakes
air bags
coilovers
lowering springs
shocks
5) Performance
Intakes
Exhausts
Headers
NOS
Turbo Chargers
Super Chargers
6) Car Audio / Video
20 or so brands
ie
pioneer
jl audio
6) Accessories
battery tie down

what databases should I make for the search engine?
do i need to make a .aspx file that would retrieve this information?
if so, what info would I put in this file?
what relationships would the databases have?

2nd question -

to create a database for my product catalog / Shopping cart :

what databases do I create?
what type of relationships will they have?
is there a .aspx file that needs to be created?
if so, what info and where do I put it on the ftp?can anyone help me?