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(http://kicad-pcb.org/) is a good one that is available for Windows, Mac and Linux.

A number of KiCAD tutorials that can be found online:

List of KiCAD tutorials

Getting started with KiCAD

KiCAD step-by-step

KiCAD documentation

Some other sources for help:

Dolf

The irc channel #electronics on freenode

All About Circuits

A few quick things to know when you get started:

Principles:

You start with making the schematic containing all components and their connections

To prevent a mess of wires crossing each other in your schematic, use busses (blue thick lines)

Add values to your components, for instance the resistance or capacitance of resp. resistors and capacitors. A 10kOhm resistor would have the value 10k and a 10microfahrad capacitor would have the value 10u.

Add footprints for each component. Before making your layout, you need to tell KiCAD the size and shape of each component. You do that by assigning a footprint. It doesn't really matter which footprint you assign as long as it fits and the connectors (pins/legs) are in the right places. So whether you get the capacitor footprint exactly right doesn't really matter, as long as the spacing of the legs is the same and the overall space it takes on the PCB is the same too. Use google to search