Investing without a steady income stream

[Gene Felten]

I'm about to go back to school and won't have a job but i'm looking into investing in homes in the south east suburbs of the Chicago area, near the city. I have good cash reserves but is that still not enough to qualify for a mortgage? 

What if I bought a turnkey home outright, hard cash buy, with tenants and I collect rent money monthly. Does that not now qualify as a steady income stream? I've heard about LLCs but i'm not very familiar. Worst comes to worst I could ask my dad to use his job as the steady income stream (I don't really want to do that though). 

If I seem completely naive it's because I am. I'm still completely new to this but aiming to purchase a property this year. I guess i'm wondering what kind of options do I have with the situation i'm in?