What is the Proper Inbound Linking methodology? Is PR Sculpting gone?

[BeytzNet]

Hi,

I know that once there were discussions about "navigating" all links top wise to the main pages - for example to category pages in e-commerce sites.

What is the proper methodology today?

One example:

Should I link out from a category main page which shows my products (a serious landing page)  to a page that explains about the product?

It makes sense but I don't want my about page to become the more important page (even though it does link back to the products category page).

Thanks