The loans that are made for the purpose of buying houses are usually called mortgage loans. I have changed your topic accordingly. I think you could start by saying that there are several different types of mortgage loans and then explaining what they are. Some of the main types are variable interest rate mortgages and fixed rate mortgages. Interest rates vary from one lending institution to another, and they also vary depending on the length of time required to repay the entire principal. A couple can borrow money to buy a house for as long a period as thirty years and even thirty-five years. Right now the interest rates are very low because of the slow economy.
If I were you I would go to a bank and talk to one of the consultants. They would be more than happy to give you some of their brochures explain the basics of home buying. All of them are anxious to make mortgage loans these days because it is one of their principal sources of revenue. Your instructor would appreciate your enterprise. You would learn a lot about home mortgages from talking to one or more of these consultants, and the printed material they would give you would simplify your project.
You might give one typical example of a young couple buying a house, showing how much they would need as a down payment, what sort of loan they might take out, and what the monthly payments would be.
You can also find a lot of helpful information in eNotes by refering to "Mortgages" and clicking on the reference link below.
When considering a housing loan the proper equation should start by putting a smile on the loan officers face. This can be accomplished with knowing the price and title of the property type which is this; a lot.