I plan on ripping out the old tub in a mobile home, and installing a walk in shower. What is the correct sequence of steps required to build up the base, slope the thinset or cement, and install the membrane. Is there a video available. I plan on ceramic tiling the stall once it is ready.

Here you go! Mortar Bed Shower Floor for Tile Showers (http://johnbridge.com/mortar_bed_shower_floor.htm)

You will use a flange type shower drain,(see image)and Blue Compaseal(see image) to pan the shower. Let me know if you need more info. Regards and thank you for ration my answer. Tom