First of all, you're getting a great start by working on it this young! Before having my own babies, I worked with children with eating disorders. So I was a little obsessive about making sure my first baby got used to a balanced diet! She's five now, and amazingly brave at trying new foods and eating a balanced diet, so my OCD paid off. Here's some of my tricks: I did give her some fruit, but only in small doses and only as "bait" until she was really eating vegetables.
1. "prime the pump" my husband would say. Once they get into the swing of opening the mouth and eating, it's easier to trick them into tasting something new. If your child is suspicious, playfully dab a drop of something yummy on his lip. He will lick it off, and want more. Give him a bite, then, when he's opening his mouth for more, try your next trick.
2. "the coat". Put some squash, or beans, or spinach on the spoon, then dip the tip in pureed fruit. It tastes sweet at first, then the new flavor hits, but it's too late!
3. "the switch"-- alternate bites of fruit and veggies.
Remember that a baby has to get used to new flavors, and new textures. It will probably take many times before he really gobbles up veggies, but it will happen, because you care.
last hint-- enjoy yourself, put on some nice music, relax, and interact with your baby. Talk soothingly, make silly faces and sounds to correspond with new tastes...(ooo! sour!), and have fun. Every new taste that is in a safe warm, environment with mommy will eventually be a pleasant memory.
Now if only I could get my third child (almost 2) to eat vegetables... I just wasn't as consistent with him as I was with the others! The only way he'll eat them is if I give him a bite of desert alternating with his veggies and he knows he has to have one to get the other. But again, I know that just getting them in his mouth and down his throat in the context of a good experience (not forced, voluntary), will help him choose to eat them later. !
Good luck!