introduce them on neutral ground - a park neither of them has been to before, dogs tend to get territorial so if they meet somewhere neutral, they won't feel like they have to defend their territory
preferably you can get them to walk together, walking bonds the pack, if they get along when they're walking, that's a good sign
let them play together, then take them home
who's ever home you're taking them too - the "home" dog goes in first - he also gets fed first etc.
hope this helps, good luck