Get the tax parcel number, go to the county planning and permit department and have them go thru everything they can with you. You need to make sure that it is a certified lot (allows you to actually build a house on it), just because it's got it's own parcel number doesn't mean you can actually build on it (I'm going thru this in Anacortes right now, I haven't bought the property yet). Also, check the wells on the surrounding lots, the county should have a record of each well and it's depth. A guy from work had a great well at about 80' until the neighbor drilled his at about 130', now every couple of years they chase each other down another 50' (Last time he talked about it he was at 225'). Strange as it may seem, being close to the pond doesn't always gaurantee good water. Check with the neighbors to find out what the water quality is, some well water tastes excellent, some not so much. Since we've been getting hit with rain pretty good the last couple of weeks, go walk the property, visualize where you want to build your house, and see if there is any standing water or drainage issues in the immediate vicinity. Think also about your driveway, if it's mush in the rain your going to be spending some decent money to excavate the shitty material and rebuild with quarry spalls and crushed rock. Power can be expensive to get if it's not close now. Like others have said, check with a title company and see if there are any leins on the property. I've never bought a house, 3 times I've bought raw land and built my house.