how do i clean my macbook?

Portables

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

Best.

Do you mean the 'cleaning' as in keeping the screen and body clean? If so, then use iKlear products.

If you mean 'cleaning' your hard drive, stay far, far away from any app that claims to 'clean' your Mac.

See the X-Labs -> Tuning Mac OS X Performance.

Clinton