12 months is the ideal age for starting SAR work with your dog. I started a blk lab last year at 6 months, he is now certified for air scent at 14 months. But I already had allot of experience training sar dogs. It is harder to train the handlers than it is to train the dogs. Handler must understand UTM and able to plot locations on a map using a grid reader. CPR, K9 first aid, Navigation, Basic first aid, basic SAR, are all things the handler need to be certified in. The days of farmer Joe showing up at a rescue sight with his coon dog and going on a search is over. Also K9 handlers who want to train their dogs in SAR work because they think he will be good exercise for the dog don't usually last long on a professional SAR team after seeing what is realy involved.
Shepard's are great for police dogs but I think they lack certain traits for SAR work. Sure they can be trained in SAR and do great at it but it takes a very special trainer and allot of time to teach them compared to other breeds. Scientific studies proved that dogs with darker color fur have better scent than lighter colored dogs. Skin pigment playes a part in scent recognition. My first choice in a SAR or evidence dog would be a black lab. Someone posted they train there dog air/scent and trailing. This is not recommended as training method for the best results in either of the categories. If you want a skilled airscent dog keep him away from tracking and trailing. Airscent dogs are mostly used when the find is so old there is no track. If you teach him to trail you only slow his training down. Yes he will trail while on a real search and that is fine. I just do not encourage it during airscent training. You want the dog trained to have his nose in the air not on the ground.