Taxes

Hello. I do not know if this is the best category to ask this question but it has a lot to do with mining.

How are miners taxed or are they? Except from usa i couldn't find for other country something about the cryptocoins and the method of taxation. For example i know that every country takes a % from the income. Do i have to declare what i make from mining?

What do you do ?
Please state your country too in the comments if I don't ask too much.