I've noticed a few people having problems so here's a few coding pointers.

Images - [img ][/img]

Color - [ color=red] (If you wanted Blue then in-place insted of red)

E-mail Link - [ email][/email]

Big Font - [ big] (This would be a good idea for all posts)

Quote/s - [ quote]

Pre-Formatted Text - [ pre][/pre]

Font Change - [ FONT=Arial] (For different font change in-pace of "Arial")  

URL  [ url=http://"Website Address"]"Title name of site"[/url] (this can be tricky)