I am a High School math/computer science teacher in the SF Bay Area. 

I want to start my own thing, and real estate is the start.I have a BS in Computer Science plus over 20 years of experience in the sector.

That aside, your basis in the property will be computed as follows.The 30k plus acquisition costs.

Skills I've learned and employed for myself and other businesses have been namely, computer programming (generally focused on web technologies) and internet marketing (email/direct, SEO, and PPC, among others).

Since mortgage interest rates compound on a daily computation, your actual basis for comparison is actually between 5.5-5.6%, which most real estate investments will outperform (you make money in 3 ways from real estate: appreciation, depreciation on a 30 year schedule, and cash flows).

While in school studying Finance and Marketing at FGCU (you may of heard of this school given their recent cinderella story) I worked for the Apple Computer Corporation.

Your total DTI ratio can go up to around 40-45% +/- depending on your FICO and other factors.So do this computation on your own and see how much room you have to add PITI.

I've actually lost feeling in my finger tips from being on a computer the past year, no really big deal,  I'm also getting a pain in the elbow as well, as they say, suck it up, no pain no gain.Perhaps that might be why I don't type with wine and roses, just a few hundred more words that new, sensitive, folks expect being coddled as the babes entering the business world think they are entitled to. 

With the double lot - yes, I can compute a "value" for it, and I understand not overpaying for it.

You'll usually need the rentals to appear on two tax returns, then you can start including then when you compute your DTI.Can you make a good living?