Some things to consider when deciding where to live:
1) Do you have children who will attend school on base? The school bus will pick kids up off base, depending on where you live. Just a side note here...the busing is fantastic. All buses have a bi-lingual bus monitor that rides the bus to and from school each day and checks students on and off at each stop--very safe and efficient! This is something you will want to verify with housing before choosing a home if you don't want to drive back and forth to base twice each day. Or, maybe you would like your kids to attend Spanish school? Living in town makes this an even easier possibility.
2) Consider your budget. Take into account the cost of utilities in Spain. We have found that electricity in Spain runs about 3 times what it cost us in the U.S. This will vary somewhat depending on the home. We have a large, older home, with a heating/cooling system that is old and inefficient. This costs more to run. Logic would dictate that a newer home with tighter windows, newer heat, etc. might warrant lower bills. We also have a pool which draws a lot of energy as well. Some homes require two separate water bills--well water for the garden, and city water for the house. Many homes have propane gas to heat the water. All of these things add up, so be prudent when you are thinking about your monthly costs...it's not just the rent, but utilities as well.
3). Negotiate to get what you want. Once you have found a house, The Housing Office will negotiate on your behalf if there are things you would like the landlord to pay for, update, etc. The answer might be "no," but if you don't ask, you will never know. We were able to negotiate yard & pool maintenance into our rent, new faucets, and permission to paint...think about what you want, and get it out in the open before you sign the lease. Decide what you can and can't live with before you come to the bargaining table. You are not going to get to move again unless you pay for it out of pocket, so choose wisely!