Originally Posted by rokkito
Start tight and play with strong premium hands initially. Let the fish and maniacs finish one another off first. Don't chase drawing hands and don't slow play unless you are holding the nuts. Use the time to study your opponents. Loosen up gradually and play aggressively towards the end game.
If you encounter a series of losses, stop playing and do something else. You don't want to go into full tilt and lose everything you won earlier on.
Monitor your progress. You should aim to finish in the money at least 50% of the time and making top placement at least 20% of the time. If you finish in the money 50% of the time but place 1st only 10% of the time, then chances are you are not aggressive enough during the end game stage.
Forgetting all the other generic stuff you posted, if you are playing 9 man and your cashing at 50% with 20% wins, you will be having a 30% ROI which is basically impossible lol. The actual winrates are closer to 13-14% with a 36-40% ITM. With 6max it's going to be the same 36-40% ITM with a 20% winrate.
To answer the ops question, there is alot of info out there, but most of it is just strategy articles that doesn't help you understand the why of why you make a certain move. You can try dragthebar.com that used to be free. Otherwise your best bet is to purchase collin moshmans book which is only around $10-$20 and go from there. It's a relatively small investment to make and you will have SNG specific info and not have to waste your time around the internet trying to find solid SNG advice.
Also, you can post hands and ask questions in here, we have a really small community, but there's some top notch advice floating around in here which will definitely help you.