**WANTED** Socializing tips

Oh my goodness!  Your pup is adorable![]
 
I made the mistake of thinking that taking Dodger to the dog park was the best way to socialize.  We are aying for that decision 1.5 years later, since he was attacked and developed dog aggression issues!  I then made things worse but cutting off all dog socialization outside of training class by only taking him hiking/hunting.  SO there really does need to be a middle ground - although I know you already knew that!
I think its great that you are taking your dog to Petsmart.  I would definately walk in populated areas as well - you may need to work your way to larger crowds but its great exposure for pups. 
I'd take Dodger to public transportation areas, there were loads of people, buses and at the station closest to my house there's a covered bridge that crosses 6 highway lanes, complete with stairs and elevators! Excellent for socializing - although we did have to work up to it!  I took Dodger downtown and to the markets where he had to get used to concrete instead of fields and the hustle and bustle of stalls and busy shoppers/workers.  Other things we did was go to dog shows/trials, watch hot air balloons take off and land, walk by construction sites, visit college/university campuses, practice OB commands outside of shopping plaza's and attend as many outdoor community events as possible like garage sales, yoga in the park, horse shows, fairs, children's summer camps etc... 
Getting back into training classes is a necessity IMO - it helps teach manners in a social setting (loads of distractions) and if you do your research, you will have a knowledgeable trainer to help you out with specific issues!  With regards to your dogs fear of children this should be dealt with right away.  I will share what I would do but I think you should find a good trainer regardless! Right now, I wouldn't allow children to approach your dog, it would be best if you could "borrow" a dog-savvy child who is willing to help.  I would start by having the child the right distance away from your dog - which is the distance where he is relaxed and comfortable and unaroused by the child.  It could be 5 feet or it could be 30!  Then just make a positive association - I would use a clicker but you can just tug/play with your pup or treat your pup for NOT reacting to the child.  Eventually  the goal is to reduce the distance between the dog and child but this cannot be rushed - your helper should understand that he/she is not to intimidate or threaten your pup by staring him in the eye or moving irraticly/teasing etc...  If you take it slow, your pup should be fine BUT its always best to have a trainer help you out directly and assess the situation (for all I know, the situation could be less serious or more serious so having someone in the flesh with the education and experience is best!)
Laslty, I would only go to the dog park at non-peak hours, its no guarantee that you won't meet with "aggressive" dogs but its less likely and easier for you to step in and protect your dog as well as confronting the owner. But your best bet would be to organize dog play dates with friends and neighbours - some training facilities will have free playdates but it's not too difficult to find owners with friendly dogs who are willing to join in!
 
GOOD LUCK

I'm probably repeating a lot of what jetty said, but these are some things I did (and continue to do):

-  finding different, dog-friendly environments for walks.   I visit at least one new place every week.   These include dog parks, forest preserves, beaches, different neighbourhoods in the city, etc.   We visit my husband for lunch downtown at a cafe that allows dogs on the patio, then walk around busy areas, go into dog-friendly shops (a lot of people stores allow dogs to come in - Banana Republic, Club Monaco and many book stores, for example).

-  I find different types of noises and sights to expose her to, such as garbage trucks, the streetcar, people on bikes, joggers, people rollerblading, kids at recess, and construction sounds, farm animals, kites, kids on their parents' shoulders.

-  Different types of surfaces (pavement, grass, gravel, sand, rocks, etc.), different types of doors (regular doors, automatic doors), elevators, bridges, different places when it's dark, public transportation.

-  Different types of people and clothing.   A lot of dogs are freaked out by people of certain races they're not regularly exposed to, people wearing hats, hoods or sunglasses, children, people in wheelchairs, etc.  

My puppy is 8 months old now and I see the effects of our socialization so clearly - she's awesome running in the woods, on the beach, walking around the city, and passing construction sites but she is very anxious at box stores like PetSmart because it's in the suburbs and we hardly ever go there.   We have to work on that more.   I'm also sure you already know this, but YOU being calm in these environments is probably the most important element in making your dog calm as well.   My puppy was freaked out about kids for a while after a little boy chased her, so now when we're near kids, I give her treats and calming signals and it has helped a lot - today we passed 30 8 year old boys on a scouting hike in the woods (with flashlights!) and she seemed totally fine with them.   Another thing that really helped with the fear of kids was finding kids with dogs in the dog park; for some reason, if a kid has a dog, is confident around dogs and isn't super gushy with Louise (my puppy), she completely loves them.  Once she was normal and calm around those specific kids, I sometimes asked if they wanted to give her a treat or throw a ball for her.    It's the kids who screetch "puppy!" that make her jump out of her skin sometimes.

class changes at a college university.  training across the street from a school at recess (or a park at peewee sport practice).  Lots of time and lots of watching with treats.  Slowly move closer to the kids as he shows you just calm behavior when training.  Be prepared to step in between him and any kid or person rushing or crowding him.  If you can find a couple of calm older kids.  Ask them to toss small bits of treats on the ground in front of your puppy so the puppy sees good stuff coming from them.  Go searching a dog obedience or kennel club in the area.  Contact them.  Ask if there are any instructors or long term members with dog savy children who might be willing to help.  It would also be a good idea to consider taking classes there as well.

Thanks for the tips everyone.  I am getting ready to take him for a walk now.  We will go somewhere new.  I never thought about taking him downtown and just walking around.  We will have to do that this weekend.  I honestly never thought about dog shows ect, im sure i can find one being that i live in a big city. 
My dog is really reactive to the clicker so that was a great suggestion.  I will borrow the neighbor kid so slowly expose him.
Ill also take him to the school on the corner.  Im usually at work at 3pm but ill just have to get up early and go by 8am....ugh!
Thanks again for all the suggestions,  it will be a long consistant process but whatever it takes, ill do it. 
 
Jo

Horse shows. Dog shows. County fairs. Outdoor concerts. Different parks. Different petstores. Play-dates with a few selected puppies (did you exchange phone numbers with any of the other people who were in your puppy class?).  Try to go to a new and different place every weekend.

One of our friends is bringing his Boxer over Monday.  We are also dogsitting next week for them.  One of our friends is having a bbq party and encouraged us to bring Sam.  That will be good experience with a good handful of people around.  Sam's not afraid of other dogs....he loves playing with all dogs, it's just kids
for the most part. Some adults he's shy with but not like kids.
We walked today at the populated park but we only seen one kid.
We'll keep at it.  We will hang out near the school tomorrow morning and practice some training ect.
 
Jo