You get green rep for posting something someone else agrees with, or for helping someone out around the forum etc etc. You can get red rep if someone dislikes what you have posted, if you receive a remark you find offensive via rep you can report it and the staff will take action.
You can't spend it on anything, the only way to get a premium is via credit card or Paypal etc.
The XD thing is simply an emoticon type deal like this =
I hope that this help some my man.
When I'm sad, I stop being sad and be awesome instead
- True Story -
X-Box 360 gamertag: xXFin4l BossXx
Add me if you wish - currently playing: Rage & Call of Duty: Modern Warfare 3
"I can't tell you not to drink and do drugs, cause they are fun. It's fun. They were, but what sucks is when you want to quit and you can't." - Scott Hall