Designing your own schematics and PCB's (printed circuit boards) is fun and a lot less complicated than you think once you get started. There are a bunch of programs to design your schematics. KiCAD is a good one that is available for Windows, Mac and Linux.

A number of KiCAD tutorials that can be found online:

Some other sources for help:

A few quick things to know when you get started:

Some design rules: