Dovetail joints are, in my opinion, the prettiest of joinery techniques. They provide incredibly strong joints that, if done correctly, don't even need glue to hold them together. However, they also require much more skill and precision to create than other joinery methods.
The two basic types of dovetail joints are through -- or full -- and half-blind. The video above shows how to cut dovetails using a table saw, but that's not the only way to create a joint like this. You can also use simple hand tools like this (I'm completely jealous of the wood shop in that video) but it does require time and precision in your work.
If you're planning on using dovetail joints often, a dovetail jig -- used in conjunction with a router -- is a great addition to any workshop. I own this porter cable version myself, and you can see the setup and how a dovetail jig works in this video.
Creating dovetails is a bit of an art form, so if you have any tips or techniques that work well for you, please share them in the comments.