Allow only logged-in users to see products pages?

I'm developing a cart for a client who is a wholesaler, so he would like to have control over who can view the products pages.

Only pre-approved customers should be able to log in and view the product pages (and see the prices) -- however, users who are not logged in should be able to see the front page and the Content / "Information" pages like About Us, etc.

We would also like to make it so that users must be approved before they can register an account and log in.

Is there any way to do this?

Thanks!

Thanks for that! That solves the first part of the problem... now how do I make it so that users must be approved before they are able to log in?