I wouldn't be concerned about he weather as it should be great, 75 in the day and about 50 at night.
If it's Barnes and Noble you are after, you have more than Chandler to choose from. (North Phoenix, Desert Ridge, west valley, east valley etc.)
If Chandler is the destination, then resorts nearby would include:
The San Marcos
The Sheraton Wild Horse Pass
The Arizona Grand Resort (further north and not quite in Chandler)
These would all have restaurants, pool scene (not so much on cooler days) and some activities for a 16 year old as you would see at various resorts around the valley. The San Marcos is located in Downtown Chandler, which has been rebuilt in the past few years with new restaurants and shops.
Basic Hotels would be centered around the I-10, Rt 101 & Downtown Chandler/Arizona Avenue and you will see all the major chains represented. These will offer better value but less in terms of things to do.
When you are in the south valley, you are not far from ASU's main campus in Tempe. Tempe is a lively little town with lots of restaurants and shops on Mill Avenue, which may appeal to a 16 year old.
Also, there are some "extreme" go kart racing locations near the airport. These offer a much faster experience than the normal go karts and they have indoor tracks, (K1 Speed and Octane Raceway)
Hope this helps.