Engagement Ring Settings is a pretty complicated subject and there’s a lot to know so I’m going to refer you to the very knowledgeable Carly Wickell over on About .com:
http://jewelry.about.com/od/choosesetting/Engagement_Ring_Settings.htm

In this article she shows you how to make diamonds look bigger, discusses all the major ring settings such as

• Pavé Setting
• Prong Setting
• Bezel Settings
• Channel Setting

All of these have plenty of photo galleries and virtual tours.

There’s even advice on how to reset an heirloom diamond.

It’s the sort of guide I wish I had found before I chose my engagement ring- I love my ring and it’s perfect for me, but I might have felt more relaxed when choosing it had I read Carly’s advice to begin with!