is everything (files, programs, internet passwords) stored on the Hard Drive? I'm looking to sell my macbook due to a corrupted hard drive. My question is, if i remove the hard drive and sell the rest of the mac will the buyer have any access to my files/programs/etc?
No, the buyer will not have access to any of your files, programs or passwords. These are all stored on the hard drive itself. The only thing that will be left behind is the firmware, but that doesn't store any personal information or any records of what programs you may have had installed. If you'd like more information on firmware, you can check the wiki here: Firmware Wiki