Does anyone know exactly how the taxes work? I just see a lot of guessing.

What exactly do you mean?

You report your income. There are various deductsion which reduce your income. Based on your income, you consult tax tables which tell you how much tax you own. There are various credis which reduce the amount of tax you owe.

Then you subtract any taxes paid from that amount and that gives you your amount due or refund.

The problems arise when you try to figure out how to report income, what IS income, what is taxable, non-taxable, etc.

I live in California. Where can I find out for the tax tables?

The %?

You'd should contact your State Department of Revenue.

The federal tax tables are on IRS.gov just do a search for "tax tabes."