As with just about anything, it's a good idea to consult with friends, family, and co-workers before you choose a mortgage lender. They may be able to put you onto one or several, whom you can then investigate to determine which is right for your needs.
If you've found a mortgage lender who offers an excellent annual percentage rate (APR), count yourself lucky -- but keep your eyes open. Some lenders may beguile you with a low APR while sticking you with huge closing costs or, even worse, balloon payments down the road.