Meeting other dogs, playing, sniffing and mooching around with other dogs is part of the fun of being a dog. I wouldn't choose to deprive my dog of that fun. I always think that one of the purest pleasures of dog ownership is watching them rough and tumble with a dog friend in a park.
I almost always walk DDog in busy city parks where there are lots of other dogs, and you'd have to be a loon to walk a dog-hating dog there. My general rule of thumb is that
a) if the dog is off lead it's usually friendly
b) if the dog is on lead, look closer. If the owner continues marching towards you and your dog, it's probably on lead because it has crap recall. If in doubt, avoid, or shout "is your dog friendly?"
c) if the other dog's owner looks like they're trying to avoid you, then there's probably a reason, which applies whether the other dog is on or off lead. For instance, my dog has a couple of breeds he hates with a passion, so we're going to give them a wide berth!
Personally I try to avoid greetings when my own dog is on lead as they can't express normal body language, and the fight/flight balance is tipped because they know they can't run away.
It's also worth reading up on dog body language, and what constitutes healthy play in dogs (reciprocity and balance being a big one!). Learning to recognise the difference between a play growl and a proper growl. Knowing that mouthing at each others faces is a normal part of play for a young dog. Learning to recognise when either your dog or the other dog is starting to feel uncomfortable and ending the play session if you notice this happening.
An occasional telling off is a normal part of a dog learning to interact with other dogs. It's one dog telling another to mind its manners, and that they're being over the top (and probably ignoring some "I'm not interested" signals from the other dog). Telling off shouldn't involve a bite; it can be as simple as a growl, or a no-contact snap.
I started off with an undersocialised 14 month old (and to be honest, not much idea what I was doing at the time!). Having let him prat about in the park with other dogs to his heart's content, he's actually got really good doggy manners now because he's had the opportunity to learn. He's far from perfect in other ways, but off lead in the park with other dogs he's very reliable.