There are really several "books" you need to develop. The Employee Handbook that outlines the employee employer relationship. When is pay day, who pays for uniforms, what are the benefits, what gets you fired, what is the chain of command etc.
Then you need an Operations Manual and you will probably want a different one for each position. What is the system for operating a 21" mower, a walk behind, or a stand on. How do you line trim what is the proper method, steps etc.
Here is the table of contents for my employee handbook
Table of contents
1. Our systems
4. Employment issues
6. Career development
Then for operations the laborer or gnome position it looks like this.
Gardeners Rules to Live By
Completing Time Sheets
Perfect Cut Every time
Magical Mulch Cover
Weed & Trash Free
Effective Cleaning Methods
Loading and Unloading Debris
Proper Pot Watering
Its a long road and if your not going to train, and demand the rules/systems are followed don't bother. It is a lot of work and its never done. The system you have for loading and unloading debris changes based on what type of truck or trailer your dumping into, just as an example.
When you change the way you do things you need to change the books. For an already busy guy its just one more thing. Not trying to discourage you I'm just saying there is a reason most guys don't go beyond the crew that they work with. Its a hell of a lot of work.
If I accept you as you are, I will make you worse; however, if I treat you as though you are what you are capable of becoming, I help you become that.