What should I ask, look for, and keep in mind?

[Alex Geesey]

I'll be meeting with a fellow investor about a Duplex (possibly triplex) they are selling within the next week or two. I have met the person at their personal residence and had a brief discussion with them about it, but nothing formal (my dad was doing work for them and I was just dropping off tools for him that he needed). I have come up with some questions to ask, but I want to make sure I'm not missing anything major.

What things should I want to know about the property?

What should I keep in mind while I'm looking into the property?

What information should I be asking them for? 

What questions would you be asking?