Hello Steemit,
I recently had a look at how the mining works in steem. Frankly it is a big nerdy job, you first have to setup a full node ( witness) and then you have to synce it ( impossible for me actually ). I noticed especially the number of hard forks in the blockchain, and how the synchronisation is tricky !
I think that mining itself is great, especially regarding the voting system and how it attributes the rewards, but still it is not as worth as mining for example cryptonotes, or some other algos who are really doing good these days.
So the best way to get SP is to be active in the community, and leaving the mining job to others unless you have a bunch of computers, because if you don't have a mining rig, it is not so interesting. I found a guy who uses up to 58 miners ! So when you know that it is just a matter of time to get a reward, this guy earns at each round ( theorically ) because of the miners number.
Now regarding the node building, there are maybe too much guides, and each one is different. I don't understand the necessity to build the whole system from scrach because it is time consuming, tricky, it asks for a lot of tutorials, can be incruate, so at the end, it is just useless, unless you are familiar with.
Happy reading :D