As you are going through the different online mortgage sites, utilize their various mortgage calculators and abundant information to determine the types of loans that you will qualify for and which you are the most interested in.  There are many loan varieties that you may be able to get (everything from a 30 year fixed to a 5 year ARM).  There are also many benefits that you may be entitled to (especially if you are a first time home buyer or a veteran).

Whatever online mortgage company you decide to work with, make sure that you read all of the fine print and that you are aware of any associated fees and conditions.  The deals that may be offered up front may not be as beneficial once you have paid for all of their fees.

As you are comparing different mortgages online, it may be important to keep some of the following factors in mind...

How Does the Interest Rate Affect a Mortgage Loan?
A lower interest rate allows you to borrow more money than a high rate with the same monthly payment. Interest rates can fluctuate as you shop for a loan, so ask lenders if they offer a rate "lock-in" which guarantees a specific interest rate for a certain period of time. Remember that a lender must disclose the Annual Percentage Rate (APR) of a loan to you. The APR shows the cost of a mortgage loan by expressing it in terms of a yearly interest rate. It is generally higher than the interest rate because it also includes the cost of points, mortgage, and other fees included in the loan.

What Happens if Interest Rates Decrease and I Have a Fixed Rate Loan?
If interest rates drop significantly, you may want to investigate refinancing. Most experts agree that if you plan to be in your house for at least 18 months and you can get a rate 2% less than your current one, refinancing is smart. Refinancing may, however, involve paying many of the same fees paid at the original closing, plus origination and application fees.

What Are Discount Points?
Discount points allow you to lower your interest rate. They are essentially prepaid interest, with each point equaling 1% of the total loan amount. Generally, for each point paid on a 30-year mortgage, the interest rate is reduced by 1/8 (or.125) of a percentage point. When shopping for loans, ask lenders for an interest rate with 0 points and then see how much the rate decreases with each point paid. Discount points are smart if you plan to stay in a home for some time since they can lower the monthly loan payment. Points are tax deductible when you purchase a home and you may be able to negotiate for the seller to pay for some of them.