It is whatever you want it to be.
Your best bet is to go watch videos and read up about it so that you learn yourself.
Have a look at WPTuts YouTube videos, a good many here will say Paul is good, here are a few for starters.
Ferdy does good YouTube videos too like here.
Both of them will have lots of other YouTube videos about it that you can browse at your own leisure.
Also, whilst on YouTube, check out Living with Pixels channel too as he should have some videos too.
People can give you hints, tips, designs, templates etc, however you really learn best by doing it yourself.
Other pages to check, like AFC own support pages.
....and many, many more.....
