I would like to make sure that my first million won't be the last one. For this I would reinvest a portion of my bitcoin profits to stocks.

3 questions rise:
1. Must I pay income tax before investing my bitcoin earnings to stocks?
2. How profitable can stocks be?
3. This is probably lame but: what stocks would you suggest to buy?

I wouldn't own stocks to trade them but to get the dividends. However, I have no idea how profitable stocks are in that sense. Can anyone tell me how much money I should invest in some nice stocks in order for them to earn me noticeable dividends?