It really depends on your website and what you are trying to sell. I often have the shop on another page when doing a client's website. I then use the home page for examples and just have one or two products, usually the top sellers.
The key is often not to overwhelm your customer as they step in the door. If you have a range of products or categories, then just give them clear signposts of where to go from the homepage to get want they want.
For example, if you are selling cakes then maybe its good to have category banners on the home page eg wedding, birthday, anniversary, congratulations etc and then you're not overwhelming the visitor with every cake you have on the home page or the shop page.