Is the camera easy to build ? I followed the instructions that are clear and was able to build it. The button that makes the film advance after you've taken a photo has been my only failure in that department.
What happens next ? You put a film roll in the camera and go out take some pinhole pictures. That's where things start to get complicated. I think this camera is too light to not shake during the picture-taking. I've tried two roll of films (50 ASA and 400 ASA) and on both occasions ended up with photos that were lacking in the focus department.
In short you will be able to try pinhole photography with a camera you've built but not in the rain and you may find yourself looking for a more heavily-built pinhole camera.