In addition to the fantastic points raised above, you should also examine the FBO's facilities and runway - e.g. have they got de-icing systems? This will be critical during the winter when several inches of snow fall onto land and will disrupt what may otherwise be a perfect flying day in CAVOK weather. You may also want to consider whether the runway has an ILS and navigation aids (e.g. PAPIs) - both of which will be useful to aid more advanced training such as obtaining an IMC or night rating.