its difficult to prescribe specific exercises in this forum, but check out these adductor stretches (see beloe linl), try to include one where your legs are straight like the seated lever
, and ones where your knees are bent like the squating grion
. The reason for this is that half of your adductors wont get a stretch if you only do one type.
http://www.exrx.net/Lists/ExList/ThighW ... hor1943047
The best advice i can give you is that if you are doin heavy squat training please make sure you have had an appropraite preperation time of at least 12 months weights before begining. Also get somebody to spot for you who knows what they are doing so they can correct your technique. i find that the majority of injuries in the gym are a result of incorrect technique, so take the time to ensure its spot on