inspection, inspection, inspection. DO NOT buy a house without a full inspection. this should take about three hours for an average sized house, and you will get a report detailing every little thing the inspector could find wrong with the house. we bought last may, and the first house we put an offer on failed the inspection miserably.
the first thing a good real estate agent will ask you for is a list of what is non-negotiable. our list consisted of 'sound foundation, dry basement'. ;D most people need a certain number of bedrooms, bathrooms, certain amount of floor space, garage, big yard, fenced yard, close to certain schools, certain neighbourhoods, whatever. figure out what you NEED in your house, and what you can slide a little on if everything else is great. it will help you narrow down the insane lists of properties that your realtor might come up with, and will help them to serve you better by not showing you houses that you would never, ever consider.