Getting pre-approved for a mortgage is the first step of the home buying process. Getting a pre-approval letter from a lender get the ball rolling in the right direction.
From start (searching online) to finish (closing escrow), buying a home takes about 10 to 12 weeks. Once a home is selected an the offer is accepted, the average time to complete the escrow period on a home is 30 to 45 days (under normal market conditions). Though, well-prepared home buyers who pay cash have been known to purchase properties faster than that.