Taxes on mining? Buaahhahahahahahahahhaha. 
+1.. The best thing about crypto is that you do not have to pay any taxes..
When you spend the coins, tax man might ask.
Yeah, they could.
What I try to do is spend most of my coins directly. I buy online in shops that accept bitcoin, buy directly from people that accept bitcoins, etc.
Do not forget that BTC (and also all the other cryptos) are currencies, use them