The very best way to avoid problems and get comfortable with your dog is to learn his strengths and weaknesses.  The best way to learn his strengths and weaknesses is to have fun with him!!  Teach him games, teach him parlor tricks, take him to the playground (I take my dogs, and they play right along with the kids), take him to Little League games, set up play dates with other dogs for socialization (use good judgement and always maintain control) -- and observe him.  See how he reacts to different situations.  Find his weaknesses and work on them.  Remember that every opportunity is a learning opportunity.  Take your dog to pet stores that allow it -- it's quite an experience!!  I'll never forget the first time Cis pressed her nose against the glass on a rabbit cage in the local Pet Supplies Plus -- she'd never seen a rabbit before -- you could see the amazement on her face!!   It's also an opportunity for learning manners.  My dogs are learning that they have to approach other dogs in a certain manner, unless released.  They would never hurt another animal intentionally, but they're huge, and there is always the possibility that they'll step on, or frighten, a smaller dog.  I don't want someone else's dog emotionally scarred, either.  In a confrontational meeting, though, I'm more concerned about Cis or Zoey getting hurt, than that 15-pounder on the end of your leash.

If you don't have any dominance problems with your dog, teach him to play tug-of-war.  Now, just like any other game, tug has rules.   Rules are meant to be followed.  This is what allows you to maintain the upper hand (I play with St. Bernards -- you don't play this game without rules!!)  

PLEASE -- don't allow small children to play tug-of-war with the dog!!

On incorporating rules, tug-of-war becomes a feat of co-operation, rather than a test of strength and dominance between dog and owner.  First, teach your dog the "Leave it" command: with the dog in a sitting position, with lots of good food treats handy (small bits of hotdog or cheese), place the tug in his mouth, give the cue "leave it", remove the tug from his mouth, and give treats and praise.  Then, teach your dog the "Take it" command -- the same way, only in reverse.  Hold the tug, give the cue "take it", place the tug in his mouth, give lots of praise, and give the "leave it" cue (this is why it's important to teach the "leave it", first).  Then, teach him "Tug" -- at this point, forget about the food reward -- your dog has!  (These commands are very simple to teach, using the clicker method -- you can ask how it's done on the Message Boards at Doggie Door to Canine Behavior.)  That's it!!  You're in business, and you've got the absolute best reinforcement tool ever for obedience work!!  What dog wouldn't work his butt off for 5 or 10 minutes, in return for playing a really rousing game of tug-of-war??  

Find his Favorite Toys!!

This game has a couple of added benefits -- it teaches your dog to obey commands no matter how hard the adrenaline is pumping, and it is also used to teach bite inhibition!!  To use the game to teach bite inhibition, just incorporate the rule that if his teeth touch you, the game ends.  Trust me -- he knows where his teeth are, and they shouldn't touch you, even accidently.  If they touch you, yelp, withdraw your hand quickly -- like it really hurt bad -- then take the toy and quit.  Don't get mad -- just walk away.   Let him think about it for about 10 minutes, and try again.  Your dog will come to learn -- very quickly -- that if he doesn't obey the rules, the game ends!!  So, it's very important to enforce the rules.
 Remember -- if at any time, your dog breaks a rule that you KNOW he understands, the game ends!   Give him a little time to mull it over, then try it again.  He'll learn.