The basic skills and techniques taught shouldn't vary much based upon age whether the catcher is 12 or 23. The only difference is that the 23 year old has seen more variations of technques then a 15 year old and has probebly figered out what works best for him, especially if he's still playing at 23.
My point being, buy the book/video or check out the onlime materials, a catcher must always evaluate other techniques/drills to make sure he's not missing out on something that works best for him. Buying videos or books are a small price to pay for gaining knowldge and/or validating your current technique/training. A lesson will cost more then a book or video.
btw I even have a Bob Bennett VHS and book on catching from a long time ago.