Definitaly get him around childern of all ages, and when you do, give the childern a few of his favorite treats to give him. And don't hold him while doing this. Let him be on a short leash where you have control. Always carry tiny treats when your out and about with him, and each time your close to any childern, ask their parent if the child could give your dog one of his treats. Generally people are really helpful that way.
When my girls were all tiny (soon as I adopted them) I had them out around people and childern all the time, and encouraged childern of all ages to hold them if they wanted. I loved when they would ask if they could pet or hold them.
