Most of my knowledge of electronics is self taught from books and the web but in many cases I have started with a published design and modified it to meet my own particular needs. 

Here are some things that I've designed and made, with their accompanying schematics and PCB layouts so that you can make them too. I offer no guarantees that any of this stuff will do what you want, although it's safe to assume it did whatever I wanted at the time I made it.