Short answer:  Very!  

Shopping for a home without getting pre-approval from your lender is like going to the grocery store and not knowing how much money is in your bank account.  A pre-approval is a written commitment from your lender on how much money they will lend you for your mortgage.  This  will help you make an informed decision on how much house you can buy.  It will help your realtor choose the best houses for you to look at during the buying process. It will keep you from wasting time by looking at homes outside your price range.  It will show potential sellers that you are serious about buying a home, and that you are qualified to do so.

Your lender will require a few documents from you to pre-approve you.  They will need proof of income, statements of assets, proof of employment, identification, and a credit score.  These things will help them understand how much money they can lend you.

The pre-approval process can take 2-4 weeks to complete.  That means that you should get this started before you even begin looking at homes.  

If you don't have a lender in mind, your realtor can recommend one.  Realtors have great insight on which lender would be right for you.  They are also very helpful on any part of the buying process you might not be familiar with.

If you ever have any questions about buying or selling a house, please contact us to help!