Renting out rooms in soon to be purchased house

[Erik Karpinski]

I plan to purchase I new home within the next month and was planning on renting out 1-3 rooms to future friends/tenants. I’ve done a little research regarding tax deductions for the portion I am renting out but was looking for more advise for precisely calculating how much of the house I can offset with depreciation for tax purposes. I was thinking that I could depreciate whatever percentage of the home was occupied by the number of renters (ex. Myself + one additional renter= depreciate 50% of home value) as they will have equal access to kitchen, living room, etc. I was also going to cover utilities as part of their rental expenses and deduct part of the utilities as well in addition to supplying furniture for their rooma which I would also depreciate. My question is what kind of documentation do I need to keep track of to avoid IRS trouble and are there other tax deductions that I could take advantage of? Any and all advise would be welcomed. Thank you in advance!