Hi how do I clean a keyboard on my Macbook

Here is the official Apple policy on cleaning:

http://support.apple.com/kb/HT3226

Ciao.

Use a low powered vacuum to clean the dirt and stuff out from around the keys

To cut the tried oils on keys and frame, use a clean cloth with a bit of rubbing alcohol on the tip and stroke, use a new section of cloth a bit more rubbing alcohol and repeat.

Do not pour liquids on the keyboard or computer

Clean the anti-glare screen with iKlear, or glass/acrylic with glass cleaner and a paper towels.