Really? You found nothing on the internet?
http://www.google.com/search?hl=en&source=hp&fkt=969&fsdt=9000&q=how+to+customize+wordpress+theme&aq=f&oq=&aqi=g1
This google search right here seemed to turn up a thing or two.
There is no easy answer as every theme is different.
Do you know how to use css? If not look that up and learn a bit…that’s what you’ll need to dig into a lot. You don’t need any real php knowledge to start learning wordpress themes. Its all about the tags in the php files and the associated css
For nice editing and developing a wordpress theme you should know PHP CSS HTML JAVA etc. including good knowledge of wordpress template tags and functions.
[sig moderated]
