when do i start bernie cranes missions gta 4?
You have to have progress enough to be in Algonquin (the second island) and yo have to complete the Hostile Negotiation and No Way on the Subway missions before you encounter Bernie and are able to take mission from him.
You like the gay guy huh? Keep playing.
you don't unlock the Bernie Crane Missions until you complete Weekend at Florian's for Ray Boccino. The first Bernie Crane mission is called Hating the Haters where you have to run with Bernie in the park and kill the guy that's been harassing him.