Checking with the neighbors is a good idea for starters, and you can also check the FEMA flood zone maps:
http://www.nh.gov/oep/programs/flood...dinsurance.htm
We had to fight a case against our bank when they claimed that we were buying property in a flood zone. It was found that the FEMA maps were from 1983 or something like that, and hadn't been updated. It was also found that we were NOT in a flood zone (we live on a steep hill, next to a brook... the brook on the map is in a flood zone but it's NOT the same brook as ours... )
The other thing you can do is ask the seller if they are paying flood insurance on their property - that should be disclosed by them and/or their agent.
And welcome aboard!!!