It depends what you are after, from your name "futurenadia" I assume you are looking for competitive gymnastics and doing well at competitions. In that case check out the equipment. Do they just have the basics or do they have the extra stuff like foam pits and tumble traks for learning the more advanced skills. Is there plenty of equipment or do you see 10 girls sharing 1 set or bars or 2 beams.
Do the coaches seem to use the equipment well and you see kids doing different typoes of drills and exersizes or are they just doing straight routines and skills.
Do the kids seem happy or do they seem stressed or scared? Are tthe coaches encouraging and supportive? or do they just telnd to yell a lot and coach through fear?
Do the gymnasts seem to be using their time well or is a lot of time wasted standing around?
Another suggestion is to call the gym and find out the schedule of the group you would be liking to join. Then go unannounced and sit in the stands through the practice and watch the interactions of the gymnasts and the coaching staff. The drills they run, the overall feel of the gym, what are the bleacher bums saying....is there a lot of dischord or a lot of positive comments?
It is always easy for a gym to put on its good face when they know a gymnast hopeful for their program walks in the door and at competitions for that matter. You really want to see what "business like usual" looks like. Good luck to you with your search!