Forum Moderators: buckworks
A basic shopping application should be able to mimic simple brick and mortar store functions like product displays, check out, payment, inventory etc.
If you're intimidated and your father does nto want to spend too much, look for outsourced shopping carts. (Amazon.Com has just released this functionality and vendors like Yahoo, Monster Commerce etc have been allowing their clients to run large stores).
You can also look at ready to install packages like OSCommerce.
Plenty of free and paid for cart software. You can even use online services (they own and host the catalog/cart).
Pay attention to details that matter like security, product organization, customer service, customer confidence builders and shipping.
Too many threads here to list but read take a stroll through other threads here in Ecomm. A ton of great information from some really talented and successful business people.