Generally yes.

You should get a Form 1099-DIV from the payer (the company or the brokerage where you have your account) that shows the amount of the dividends. There is a box on there called "qualified dividends." If you have any qualified dividends AND they fall into the 10% or 15% federal tax bracket, then they are taxed at 0%.

They are also subject to state taxes.
Generally, yes. But there are exceptions. Contact your tax accountant for details. Mutual funds and certain investment vehicles like REITs have special rules however - Dividends paid to owners of stock in US Cos (the normal people, normal owners of stock situation) are indeed taxable. BUT it is NOT taxed as ordinary income. Generally it is taxed at the special capital gains rate of 15% (a change as of I believe 2004). There are some qualifications: Must have owned for 61 days; if your already in a low tax bracket, you get a yet lower - 5% - tax rate on the dividend. A note, Dividends received by one corporation from it's investment in another are also treated differently...generally a 70-80% DRD (Dividend Received Deduction).