Hey,
There's loaaaads to know, and I was on it for several months in my last year of uni.
A good start is
http://reclaimyourskin.co.uk/ - I myself wrote a little blog on there for people like you to read and add to when you start on the drug.
It can have bad side effects but this will be explained to you (extreme dry skin, dry scalp etc.) it basically reduces dramatically your skins ability to produce oil and therefore stop the acne.
I did have a lot of submissions on that site, but it seems they've redesigned it and my content isn't there anymore.
My skin used to be pretty bad and therefore I lacked confidence! Wish I went on it before uni, it wasn't until my skin was clearing up a fair bit that I actually met someone (probably a mix of improved self confidence and nice skin!).
Before (I have very few photos of my skin before it got better!)
Now:
How old are you and how serious is it?
I tried all sorts of creams etc, various antibiotic tablets (oxytetracyclene), and none worked.
I met a dermatologist through the NHS and had my bloodtests, then went onto a course of tablets.
In a nutshell, these were the phases;
1-2 weeks - nothing much, skin starting to dry by the 2nd week
2 weeks onwards - incredible dryness of skin, lips cracking, random nosebleeds where the skin inside your nose just randomly cracked! (had about 5 in total).
You get a phase of really nasty spots, but this clears and it was suprising how fast my skin lost its redness and cleared up.
6 months seems like a long time, but it really flys by and is well worth doing imo.