if you know things he likes (especially if you like the same things) thats a good place to start...be yourself, and let him be who he is...dont walk into it with pre-conditions or expectations...relax, its just conversation
hard to read people somtimes, might be that hes nervouse too...give it time, dont appear to be bothered by the changes and delays, just "glad to see him and hope you can hang out somtime"
Ask open ended questions to get him talking. Questions with yes/no or simple answers won't do it.
Un button your blouse!