Here are three great sites to advertise your home for rent or sale, by owner.
This is a VR SAM site FREE to our Military Families! You can attach your homes listing at over 440 bases world wide by using drop down menus. You can also use jpeg photos. If you are listing your home with a Realtor, ask them to add the listing to moresam as well (also free for them).
Excellent site with high visibility, designed similar to moresam. There is a reasonable fee for use, but well worth the money. http://www.ahrn.com/
The DOD Automated Housing Referral Network is free also, but you must be a military member to use it.
You may also want to consider Craig's List (free) and the FSBO sites which are not specifically targeted to the military community.
We hope this helps!