How To Get My Dog To Behave

I love my dog Stoopot, but he does not know how to behave. The worst thing is, he pulls on the leash, and he is strong. He doesn't look that strong, so it is a little deceiving. But if you aren't paying attention, he could pull you down. I have to be really careful when it is icy outside. I am thinking some dog training advice would help with this. He is not a young pup, but am hoping that maybe old dogs can learn new tricks. I am reluctant to let others walk him, because of this problem, but it would help me out if I thought others could do this too. Something to think about.