This is actually a really common fear. I have professional dog-training experience, and you’d be really surprised at all the people who love their dog but are basically terrified of other dogs. The only thing I can suggest is what has been suggested previously, especially the fenced dog park, older/mellow dog idea. But don’t get a puppy unless you are 110% certain that you can and will love, care for, train, and afford, both financially and emotionally, to own a dog.
Here are a few suggestions- when approaching a dog, read the dog- tail straight up, legs squared, looking right at you- this is a dominant dog who may not appreciate your invading his turf. Never make eye contact with a strange dog- instead, crouch down, look away, and scratch the dog’s chest. (Petting a dominant dog’s head or neck can seem like a threat.) Always ask the owner if you can pet the dog, if s/he’s friendly, etc. A friend’s older Lab or Golden would be an excellent choice. If a dog comes up to you, tail wagging, mouth hanging open, tongue out, ears relaxed, you’re safe to pet.
Your own body language is probably keying the dog in to how you feel. You’re most likely tense and rigid, making quick or jerky movements- this looks threatening to a dog. Just try to relax- move slowly and deliberately, breathe deeply. Look away from the dog, act nonchalant, like you don’t even notice the dog is there, and couldn’t care less what it does next. This tells the dog you’re not about to do something crazy, but you’re also not a subordinate.
Get a few good books about dog behavior and training- books by Stephen Budiansky, Stanley Coren, Brian Kilcommons, and John Ross are good.
On a side note, anyone who won’t put the dog in another room when s/he’s making a guest uncomfortable or just being a general nuisance is a complete asshole. They’re giving dogs and dog owners a bad name. My dogs are family members, but like any other family member who’s being a pain in the ass, they get told where they can get off.
Good luck. If there are any obedience competitions in your area, maybe you could attend one and talk to some owners- obedience comp. dogs usually have very good manners and “people skills”, since they have to deal with this stuff all the time. Visiting a breeder could also be a good idea- puppies are irresistible, and if the breeder’s a good one who truly wants to promote their breed, they’ll want people to know how great their dogs are.
Also, I hope I don’t get flamed for this, so I’ll issue a few qualifying statements right now: every indiviadual dog is different. There are no guarantees. I like every single breed of dog, and have met good and bad members of a lot of them. It’s just that due to breeding, historical function, owner personality, media hype, etc, etc., that some breeds can be said to be more or less friendly than others. But again, no guarantees- I’ve seen vicious Golden Retrievers, and I own an incredibly sweet, friendly, trustworthy pitbull. So here’s a list of some good breeds to meet, and some not-so-good breeds for people who are afraid of dogs. Mixed-breeds are slightly tougher to predict, but most are absolutely great dogs. (Shelter dog plug inserted here.)
Generally Pretty Friendly:
Golden Retrievers
Labrador Retrievers
Pugs
Cavalier King Charles Spaniels
Newfoundlands
Bloodhounds
English & Irish Setters
Dominant & Territorial
Rottweilers
Akitas
Chow-Chows
American Pit Bull terriers
Airedale Terriers
Chihuahuas (I’m not kidding.)