My little one was interested in the potty from the time he was 18 months, but we didn't have any success until a few weeks ago when we decided to go "naked" at home. If it's warm enough in your house, I'd absolutely recommend this. You'll be able to see the signs that he's ready to go faster, and he'll see what the peeing thing is actually about (also, some kids get really upset about peeing on the floor, which helps to speed the process). I'd snatch him up and carry him into the bathroom when he'd start to go and say: (with the best smile in my voice i could manage while remaining urgent) "pee in the potty! pee in the potty!" After 1 day, he started going on his own, and after about a week, we had very few "accidents" (usually when he's really enjoying playing with something).
i didn't use any stickers or treats, just lots of praise and applause immediately after he went in the potty. i also got papa to make a big deal about it when he came home from work. even grandma gave him praise and attention about it when we saw her on the weekends.
a couple of caveats, though: he was about 2 1/2 when we started, so you might still wait a while. and it does require an eagle eye for the first couple of days--if you have a friend or grandma around who can take the 3 month old for a weekend while you focus in on potty training, that could help jump start things. also, expect him to be trained at home, but still need diapers when you're out--there's a several month lag a lot of the time. lastly, #2 is a whole other thing--my son's been accident-free for a while now with pee, but he freaks out about going #2 in the toilet and still won't choose to do this on his own.
good luck!