What degree of detail do I have to keep in order to properly declare my taxes regarding cryptocurrencies? Every operation, investment or ICO has to be recorded? I also have done a bit of mining and I have no idea on taxes regarding that.
Without opening a legal entity, you cannot prove your costs of acquiring mining equipment. This means that all amounts obtained from the sale of coins will be treated to your income and your duty is to pay their taxes. Such legislation is in my country. Perhaps in another country otherwise. But I think the rules are about the same everywhere.