I've sewn a side-seam pocket with a side invisible zipper a couple of times now, and I didn't want to have to figure it out again. So I made myself a little tutorial.
First step is to finish the edge of the left back (I put my zippers on the left) to where the bottom of the pocket will attach. Finish the left front edge to the top of where the pocket will attach. You can do this later, but you'll have to keep the zipper out of the way.
Then attach the left front pocket and both right pockets as normal, including pressing, finishing edges, and under stitching.
Now attach the invisible zipper as normal to the left back. This is where the easy part ends.