For instance, we know roofs are critical due to the year round rain.

@Eddy RamosIf you're challenged by the IRS, which is quite likely when you have a W2 job, you will need to be ready with two critical items:- written statement from your employer showing how many hours you worked for your job- your own written log showing how many hours you worked in real estate - actual work, not reading BP posts or listening to REI podcastsThe second number must be higher than the first.

But first what are the critical questions?

As with any tenant selection.... it's critical to verify what the applicant is saying and what is written on the application by doing thorough background checks.

We use facebook and google my business. signage is also critical. 

I noticed as I was reading responses that people were giving you a lot of advice but there are some critical questions that need to be asked first, and I appreciate @Allie Pfannenstiel's post, as it actually directly asks some that i was already thinking about. 

I would think the critical factors here would be employment and traffic drive times.

When moving a tenant in, it is easy to skimp with the move-in inspection check list (or "Property Condition Report", as we call it) yet it is a critical document.

They will stop reporting issues; they will make half-way repairs that will ultimately result in more damage; they will use unlicensed people for critical technical repairs such as electrical, appliance, plumbing repairs, and even substandard flooring or other repairs that could cause injury.

If you're looking at multifamily properties over 4 units, this is going to be a critical number to know as the banks derive the valuation of a property in part from the NOI (NOI/Cap Rate).The Cap Rate is going to be dictated by your local market for that particular asset class, so there's nothing you can do to control that, but you can control the NOI by increasing revenue (raise rent and additional income sources (parking, laundry, pet fees) and by decreasing operational expenses (spend less to actually operate the property).One of the biggest expenses you'll have on a property are the utilites.