Only on 2+2 could a request for a sample loan form turn into a multi-post pissing contest.
Here's a couple:
google link
http://www.medlawplus.com/legalforms...-loanagree.pdf
http://www.lawdepot.com/contracts/loanagree/
Not that you asked, but I've loaned money to friends in the past so 2 unsolicited suggestions:
1) It helps avoid any awkwardness later if at the very least you specify in writing an exact date the loan is due to be paid off & what penalties like a high interest rate or $ amount that are incurred if loan is not paid off in time.
2) Charge interest that's more than you'd get on your own and less than they'd pay to a bank.