1. Trulia Still my number one recommendation for finding rentals in Carlisle. Trulia has more rental listings than Zillow.
2. Homes.mil Carlisle is home to the US Army War College (AWC). 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.
Valuable real estate search tools that didn't make the list: AHRN.com (The second best website for Army War College / military focused listings; similar to Homes.mil) MilitaryByOwner.com (great military housing site, but fewer listings because owners must pay to advertise here) NextDoor.com (community based listings) 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) Carlisle Area Chamber of Commerce (listings & local tips) You can also check out the classifieds at PennLive and CumbLink. A final resort is looking for temporary housing (ex. Airbnb) for a place to live until a suitable rental becomes available. Find more tips like this at my Renting 101 Rental Search Tips article.