Emerald Aeris is completely right about positive reinforcement. It is by far the best way to train and the best way to get good results, plus the trust of your dog. However, I will say it again, "shock" collars ARE NOT cruel unless misused. When used on the lowest setting, which you shouldn't have to go above unless your dog is aggressive or putting someone in danger, it isn't even physically painful. It feels like a tingle, and yes, I do know this, because I have felt it, on every level. It was a requirement at my job to feel whatever the animals might feel, which I think was a good requirement.

E-collars are an excellent training aid, but only if you know what you are doing. I still would highly suggest you consult with a qualified trainer before trying to use one. There are a few different models out there, some less quality than others. The ones we used most often were Tri-Tronics, which will set you back a few hundred dollars, and the Dogtra. The Dogtra is about $200 and would more than likely be good enough for what you need. Along with the physical stimulus, it also has a 'pager' feature on it, which can be used for positive reinforcement.

I cannot stress enough that electronic collars are cruel only when misused. You don't have to use one to get the results you need, but you DO have to put time and dedication into your training. Consistence is the key. And what you're trying to teach, the recall, is the most important command the dog will ever learn, so it is VERY important that it is done right. Screw it up, and your dog might not want to ever come when you call. Again, as Emerald said, leaving a dog, especially a young, untrained one, outside on its own isn't good in the first place. Have treats with you every time you call the dog to you, and give him heaps of praise when he comes, so he learns that coming when you call is a very good thing. And NEVER, under any circumstances, EVER yell at or hit the dog when he comes to you. If he did something wrong, don't call him to you to fuss at him, or he'll learn that coming to you is a bad thing.