The material cost me about $500 (for dimensional, not three tab shingles) and the insurance check was for about $1400-$1500.

Redfin is actually an excellent source for info on the house - mortgage numbers, taxes, insurance, etc.

Here's a link with a video about all the new changes throughout CA in regards to ADU's. http://www.hcd.ca.gov/policy-research/AccessoryDwe...

My plan to getting started is to buying a single family house 4-6 bedrooms for around 200-300k  and renting out each bedroom for around 600 a month the area I'm looking to invest in has 2 major university's and 1 major collage so id be looking to rent to students , I do not have enough money to put down a conventional 20% down payment for an investment property so id have to put down 5-10 percent down with Mortgage insurance and put it as my primary residence but realistically I wouldn't be living there. 

You might run into issues with insurance with the pool.  

We put 1k a month into the fund, and it's used for repairs, maintenance and other expenses, not counting taxes, insurance or mortgages. 

Your expenses after taxes remain the same as well so you can save $160 per month (until your real estate property taxes and insurance increase). 

@Troy Schwamberger you are correct. the 1.2x is a bank standard for lending, even if you are at 1 and not bringing home money, you essentially are making money. your tenants are paying for the house ( adding equity) the bills are all being paid for to run the property, pay insurance and taxes. you also get to depreciate the property and if you do any improvements to the property or repairs that gets deducted or depreciated while adding to the basis of the property, if it is a capitol improvement.

Mortgage with P and I, water, sewer, insurance, taxes, electric and such comes to $3569. 

That’s not taking anything out for tax, insurance, repairs, PM, vacancy like it should.