Long-term I'm hoping to build a portfolio of cash-flowing properties that produce enough income to live off of! 

My recommendation would be to get into the local REIA AZREIA.org they are one of the best in the country and you can learn tons and meet seem great contacts.I have looked at some of the 'flips' in scottsdale and in my opinion many of them are Subpar so if you produce a superior product than I would imagine that as long as you can find the right deal you will not have any problems.  

It produces 6% return.

Doing this, you *might* be able to find a few properties that will produce the cash flow you are looking for. - Option B is a little more farsighted, and a little less "analysis" based.

@Jeff Thompsonwhen you sell investment owned by the IRA - the gains are sheltered from taxes (because IRA is tax-deferred vehicle) and when IRA-owned investment produce income or cash-flow - it must flow into the IRA and also will be sheltered from taxes (unless the income is unrelated business taxable income). 

I am interested in learning how to either flip houses or invest in property to produce long-term income now, so that when I finish graduate school my wife and I can best invest our income early on. 

I have finished all of the courses and tests to become a licensed real estate agent but have not currently found a broker.The last thing I wanted to mention is that I hope to own 10-20 income producing properties in the next 10 years.

@Ryan York - I agree with you that while the purchase price is lower than people from more expensive areas are used to, SFR still is not producing great cash flow unless you're buying serious fixer-uppers, in which case there's a ton of competition.

In short this means that it produces more energy than it consumes.  

I should disclose I've spent the last five years in a technology sales role, and have grown to be the highest producer in our southern region.