Soldering copper pipes is a more advanced DIY skill, but a great one to have if your house contains copper plumbing. Here's a complete walk-through on how to solder pipes.
Soldering might seem intimidating because of the torch and metal, but it's actually a pretty simple process, and fairly cheap to get started with.
This video gives an overview of the solder process, materials, tools, and a few good tips on working with copper pipes.
How to Solder Copper Pipe [YouTube]