One of the easiest things to do when building agility equipment is to make jumps.
You can make really rudimentary jumps using a broom handle and two objects to rest it on. This works really well in the house. You can then situate them between doors to teach your dog to jump up instead of running around. To prevent them from crawling under, hang a light sheet over it. Works wonders to teach the initital jump over. 🙂
To make more “standard” jumps, or adjustable jumps here are some sites to go to. You can look at what is sold, and then figure out easily how to make them yourself.
Anyways, check them out. Not too hard to do. Usually the first thing that agility enthusiasts will make.