How do I start PCB designing?

For a Beginner in PCB Designing, start with Simple & user friendly soft-wares like Eagle, Proteus etc. If you are good in circuit reading & drawing, you can easily make schematics in the PCB, through which you can create net-list & make layouts for the circuits. There are basic rules to be followed while making Layouts in PCB. something like this, you can find more stuffs in Net.

The Engineer’s Guide To High-Quality PCB Design

Practice practice Practice…. it is the only way to become a good & professional designer. In this internet Era, its not much difficult to learn one thing easily, go with with more tutorial(I did the same). It matters how you take up the concept & how you follow it up. Try starting with simple designs & increase your scale to complex designs. Try different tools & stick with the tool which you are comfortable.