In iBank, a loan account is a special account type with a setup that lets it calculate the amortization schedule. iBank makes the assumption that a loan is money you owe others, and in the current version, it doesn’t work the opposite way. In other words, iBank doesn’t amortize loans made to others. You’ll have to calculate the interest/principal schedule on your own, but there are numerous online amortization calculators that make short work of it.
To track such a loan, the best thing to do is create an asset account with a positive starting balance equal to the initial amount of the loan. Ideally, the transaction in your account from which you paid out that money will be categorized in iBank as a transfer into this asset account. Then, each time the borrower pays you back, you make a transfer from that asset account into your checking account (or wherever you actually put the funds paid).
That way your net worth is unaffected, you have a record of the payments, and your balances in your deposit accounts remain correct. You can also add another “deposit” (or transfer) to reflect additional funds lent to the borrower.