Do you own the vehicle outright? Then you just sign a line on the back of the title and give it to your friend. They will then need to go to the DMV register it, pay tax, and submit change of title paperwork. AFAIK, you can write a number it was sold for, somewhere, but they will take the book price for taxes if the listed sale price is lower than the book.
If it's still under loan, you will need to call your bank, tell them you sold it and ask when/how you can get/transfer the title once it's payed off. You may be able to set it up with the bank to meet your friend with the money, at one of their locations, where you do the bank's paperwork and transfer the money. The actual title may not ever even tough your hand.
If your friend needs a loan, then it's more involved with the banks transferring money and title, I think.