Credits are gained every time you make a post.
You can use your credits in the vbookie threads to bet on all kinds of sporting events.
For example you can bet some of your credits on the Haye boxing match that is taking place tonight. Or you can bet on any of the UFC 132 fights taking place tonight.
UFC vbookies are located here ~ http://www.mmaforum.com/ufc-vbookie-betting/
Strikeforce vbookies are located here ~ http://www.mmaforum.com/strikeforce-vbookie-betting/
Bellator vbookies are located here ~ http://www.mmaforum.com/bellator-fc-vbookie-betting/
There are also vbookies for Japanese MMA, and K1, which are located in their own sections.
The non MMA vbookies section is here ~ http://www.mmaforum.com/sports-vbookie/
If you need any more help then just let me know