What are the requirements to claim the expenses for my home office as a deduction from income tax.

I am a subcontractor doing Business Analyst and Project Management for a company that develops software. I am doing work from my home office on a regular basis. I would like to know if you have a BASIC list of expenses I should list and gather documents for to prove. What are the requirements to claim the expenses for my home office as a deduction from income tax

Please use link below to see if you are eligible to deduct home office expenses as well as clarification of what they are and how to apportion them.
Can I deduct home office expenses?