How to prepare your MacBook for re-sale or to give away.
Recently someone asked for help on wiping her MacBook so she can sell it. So what do you need to do before selling your MacBook?
This is what I did on her machine.
1. Backup w/ Time Machine
2. De-authorize iTunes. -- You only have 5, why waste them.
3. Log-out iMessages.
4. Download OSX create bootable USB. -- I borrowed my brother's bootable Yosemite stick.
5. Erase Mac using Find My iPhone app (or iCloud) -- I think this is the easiest way to delete everything on it.
6. Re-install OSX. -- After step 5, you will have a computer without an operating system. You can re-install using your recovery partition but the whole OSX will have to be downloaded (that's what happened to me first) that's why it's better to have a bootable USB stick with the OS ready.
Here is Apple's official guide, which I did not follow, because I only thought of searching for it after I had finished. http://support.apple.com/en-us/HT201065