The implementation of BYOD requries having a BYOD plan.  You should develop a BYOD plan that fits your small business.  As a minimum a BYOD plan should cover the following areas.

Liability: 
Who is liable for paid apps, loss, damage and maintenance of the device.

Security: 
How the device will be secured physically and virtually.

Equity:
Level playing field between those who can afford and those who cannot

Overtime: 
Does using the device after normal work hours constitute overtime.

Apps: 
Which apps are allowed for business use and which ones are not. 

Repair: 
Internal v. external IT support.

Cost: 
Which costs will the business incurr and which costs will the owner incurr.

Autorized devices:  
Identify what type of devices will be authorized on the company's network and given access to company resources.

Productivity Tasks:
What tasks are allowed to be performed on the device in support of company business.

Privacy: 
Determine how privacy data will be protected.

Termination: 
What are the steps that will be taken to protect the company's data  when an employee is terminated.

Compliance with mandates (PCI, DSS, HIPAA, GLBA):  
How will the company comply with these regulatory guidelines.

 

These are BYOD template examples that you download and edit to fit your situation.

The White House BYOD Policy example
Good BYOD Policy example
U.S. Government BYOD Policy example