advice on selling macbook please :)

hi all,

I have a few questions I bought a macbook late last year that has snow leopard (i think) and am basically computer illiterate, just use it for shopping and itunes, anyway i am thinking about selling my mac to a friend of a friend but am a bit wary because i have done a load of internet shopping and have a lot of credit card details and social welfare passwords saved on my computer etc. Anyway i was wondering is there anyway i can clean/erase my hd but without deleting my songs in itunes (my friend wants me to keep these for him) ive been looking on google for a few tips and heard of disk utility but am not sure what this is, and if it only gets rid of stuff thats gone directly through the trash or does it also cover website visited. i.e. business email/contacts, shopping on topman or nike with my credit card details or passwords signing into my revenue site (tax site). i always reset safari and empty cache after shopping online but is this enough?

once again i know very little about macs not even sure what a disk or a volume is so please reply in basic terms!

PS: any suggestion of anything else i should do before selling a mac would be appreciated.

thanks guys

Before you sell the machine to your friend you can wipe the hard drive and reinstall Snow Leopard. That will give him a fresh machine to start with. It's illegal to leave your iTunes material on the machine for someone else so be sure to back it up somewhere before you erase the hard drive. Also, include the original DVD set that came with the machine.

Regards.