Oh yes, get him neutered. Not only will he be a healthier doggie who'll live longer, but you'll also curb most male behavior issues. In other words, he'll live longer and you'll be glad! Unaltered males are one thing I personally find pretty gross. They do yucky things and are virtually impossible to control if there's a female in heat anywhere in your area.

As everyone else has said, most vets recommend the surgery around 6 months of age, or when the testicles have fully descended.