Helpful Tips For House Hunting?

Over the past week, we began our search for a home! It has proven to be challenging and there are a lot of new things we haven't had to consider before. We have always rented homes, so I have gone into leases thinking "Can I deal with such and such for a year or two?" I've never had to consider if certain features in a home would bother me for 20 years. With every new house, I have to not only consider the cost of the home itself, but also the cost to fix anything that may need a little TLC.
Besides the obvious considerations (such as layout, square footage, bedrooms, etc), I've had to start weighing out what we value most. What if the house has nasty green carpet, but we love everything else? What if the only thing "wrong" with a house are cabinets from the 1970s? What if the house only needs a new roof? We've begun trying to see the potential in the home, and figuring out how much it would cost to make each house into something we would love. It's been very stressful and overwhelming.
So that's where you come in friends! I would love to hear your advice about all things "house hunting"! What are the easiest and less expensive issues to fix in a house? What are major items that would be deal breakers for you? Are there things that have come up since you purchased your home that you wished you knew in the beginning?
Any advice or helpful tips would be greatly appreciated (: