First and foremost, get it in writing! Set forth how much money is being lent, what the interest rate is (if there is one), what the payment terms are, and when the borrower is considered to be in breach. You do not want to part with the money, only to be told later by the borrower:
Second, see if you can get the borrower to put up collateral for the loan, especially if the money is being lent to buy something. If it is for a car, be sure to file lien paperwork with the New Jersey Motor Vehicle Commission. If it is a home, have the borrower sign a mortgage document and record it with the county clerk. For anything else, get a detailed description of the collateral, including serial numbers if available. Anything that helps identify the collateral later is required. Then file a form called a UCC-1 . Not only will this give you some recourse in the event of breach, it will also protect you should the borrower file bankruptcy.
Third, and finally, talk to a lawyer! The above advice is good, but if done wrong may not help you. Be sure to have it prepared by a professional so that it is done properly. The fee will be money well invested, and you will thank yourself later if things go south.