#3 Homes.mil Carlisle houses the Army War College. Many owners list on military housing websites instead of to the general public. AWC refers renters to this website first, so it's one of my top resources when looking for Carlisle rentals.
#4 AHRN.com For reasons similar to Homes.mil, this is one of the first places rentals are listed for exposure to military families.
Honorable Mentions MilitaryByOwner.com (great military housing site, but fewer listings because owners must pay to advertise here) WalkScore.com (good for walkers, bikers, and neighorhood info) AreaVibes.com (rate your neighborhood by categories you choose) Zillow.com (similar to Trulia but with fewer listings. Also associated with Hotpads.com. Good iOs / android apps)