Before viewing any home, it is always best to view all available information online, look it up in the town records, and drive by it at least twice, ensuring that you view it at different times of day.
During your first viewing you should examine the appliances, water pressure, heating system, foundation, pipes, electric box, the state of the walls and ceilings, and the condition of the outside. Check the beams in the basement for mold and don’t be afraid to pick at the wood to ensure the beams are dry and stable. Open every drawer, try every door, and be wary of water damage and large cracks in the walls or floors.
Take your time. A realtor in a rush is in the wrong business.
If you think it merits another look, try going back at a different time of day and if possible, bring along a friend or relative who has either purchased several homes in the past or has a knowledge of construction.
Ask questions. No question is too silly or inconsequential. Remember that your realtor should be willing to look everything up and should be able to report back in a few days.