Would like directions on how to build a cement shower with no door, just a walk-in.

Here is a link to a site with some good instructions, may not be the exactly lay-out your looking for but the basics are all there

How to Build a Shower Pan

I've recommended that link for years. This guy just does a great job and we don't have to type a book all over again. It is not built with cement like a sidewalk but with mortar, called mud by most.