Help Trying to Purchase Older Apartment Complex

[Ambrose Brooks]

Located in Texas and am looking to purchase my first apartment complex. Have a potential deal to purchase an older complex from the late 1960s between 25-30 units, I have various operating costs from the seller: insurance, property taxes, gas, water, electric. What other fees should I verify. Also how should I determine maintenance costs and what sorts of capital expenditures am I looking at over 10 years+ that I need to consider. What documentation should I get from the seller to verify all this? What sorts of cap rates are really good, anything above a 7%? Cap rate doesn't take mortgage payments into consideration right? How much are management costs typically if we get someone else to run it? 

Anyways just looking to make sure I check out everything before buying and any guidance is appreciated. Thanks!