Below is one example process of creating a PCB.
In other words, decide which devices you want to use and what you will need to construct your circuit. If space is a constraint, picking the right device package is crucial.
Once you have all your devices. Create a simple Excel sheet of the various pin-outs from each of these devices. The goal here is to create a reference of which pin goes to which. This will greatly increase your accuracy in the next step…
You will need to download and install a schematic-and-layout-program.
Using your schematic program create any needed device libraries and then create the schematic for the board.
Once your done with the schematic, layout is just routing the traces around the PCB as efficiently as possible.
Some tips for good routing.
Below are some of the most popular ones in the USA. If you have a resource in your area please add to the list below.
Training by Freescale on Effective PCB Design
General PCB design Engineering Articles from Quick-teck PCBs