By far and away the easiest way of making cash is via Nicehash but it's not the most profitable as your basically paying them for making it easy for you.
That link gives a rough idea of the returns you can make with your card.
If you download the program from the link above and run the benchmarks it will work out what the best thing to mine for you is and automatically do it.
You just need to setup a bitcoin wallet from somewhere else (just google bitcoin wallet and it will bring up a load you can select from like coinbase/jaxx etc), Then put that wallets address in the wallet section of the program and away you go.
All cards mine different things at a different rate though so not all cards are worth doing and depending on your card you want to change the settings on it as well (my 1080 cards, for instance, I under power to 66% and bump the memory up.
Then when you've earned enough money for them to send it (think its around £18) they will send it to your bitcoin address and then you can sell the bitcoin for cold hard cash or keep it and sell it at a later date.
Regarding your link it's not worth mining Bitcoin with a GPU it would now take too long you are better off mining other coins/things (AMD cards with generally mine Ethereum for instance) like I said Nicehash make it easy for you and you basically mine the Ethereum and they will pay you in Bitcoin for it and because of that you won't earn as much as you could if you mined it yourself and then exchanged it for bitcoin and then sold it.
It maxes out your GPU tho so when running it you won't be able to play any games on it (browsing etc is fine) you also may want to check your temperature on card etc because of this. Like I said tho you can generally lower the power and increase the memory and it will run cooler and use less power than running it at 100%.
Personally my 1080 near my CPU gets to around 70c, 1080ti gets to 61c and the 1080 on the outside of my case around 55c. The 380x I did have tho used to hit 80c unless I bumped up the fan speeds.