if anyone please can help me here,i need a two tone affect (black and white if possible ) for my background..also where do i put it cheers
Can you explain a bit for in depth? I'm not sure I quite understand what your trying to accomplish...
All layout changes are done in admincp. Most likely you'll edit the themes global.css.
To familiarize yourself with CSS I suggest you use the official W3C site.
http://www.w3schools.com/css/
Two-tone is probably easier to doo with an image background (with the image made using a gradient in photoshop or such software)