Without seeing an over all plan, and understanding exaxtly what you've done so far, I'm a bit confused as to why you are not installing Tees at your various connection points as you install the pipe (unless you're trying to use a pipe-puller). But then, I don't understand what's wrong with cutting into the pipe to get Tee's installed. And I'm completely clueless as to why you think you must have "rigid pipe" just because of the terrain of your property (unless you are trying to install this suspended rather than burried).
And again, without knowing the full details of your plan, I would personally want to use 1" PVC for the distances you are talking about rather than 3/4" to minimize pressure losses over the distance you are talking about. (If you've already purchased the 3/4", haven't installed it, but can't return it, I would suggest starting with 1" near the water source, and once you are far away from your water source, drop down to 3/4" as you get closer to the distribution points).
As for how to connect drip irrigation to 3/4" or 1" PVC supply lines, I used some pipe-thread to drip tubing connectors I found at Lowe's. Basically, this connector has a 1/2" male pipe thread on one end, and a special twist connector on the other end designed to hold 1/2" drip irrigation tubing. I ran burried PVC out to the distribution points and ended the PVC at a 1/2" female pipe thread fitting. I then built a section of 1/2 copper pipe that would run underground for about a foot, a 90 degree elbow to turn and head to the surface, and another 90 degree elbow at the surface to turn parallel with the ground. The copper included female pipe threads at each end. The copper was connected to the PVC via a short piece of funny pipe, and the drip tubing was screwed into the other end of the copper tubing. This allowed for a rugged section of pipe coming up out of the ground (i.e. something that could stand up to being stepped on, weed wackers, and isn't attatched rigidly to the much more breakable PVC).
But to back up even farther, I'm going to suggest that you use 1" PVC rather than 3/4" PVC, at least at the start. Since you are talking about some pretty good distances (i.e. hundreds of feet), you might want to run 1" PVC to minimize pressure losses