Hello
I can't give a you a specific document, but the first thing you should know is that when you will enable stp, it will cause network interuption.
mstp is the default now, and i suggest you keep this.
The first thing you have do to is to assign a root switch in your spanning tree topologie. you can choose this by configuring the lowest stp priority on that switch. (Your core switches should be the root)
After that you can enable spanning-tree on all your other access switches, just make sure that the stp priority on your access switches should always be higher then on the core switches.
After you enable stp on any device it will calculate the best path to the root switch, this proces will disable the ports for a brief time (few seconds).