Hey there! There's not really a guide, but it's not too complicated, so I can just tell you how it works real quick:
There are three routes, A (humanity), B (the fae), C (neutral), and the split happens towards the end of Chapter 6 during the conversation with Vynn. If you want to experiment, it'd be good to make a safe file before that point.
To get route A, you need to have a good relationship with Az'Lean, and during that conversation with Vynn, decide to support humanity above all else, which includes being willing to betray Maeve.
To get route B, you need to have a good relationship with Maeve, NOT tell Az'Lean the truth about you, and during that conversation with Vynn, decide to support the fae above all else.
To get route C, you need to have at least a neutral relationship with Maeve, and during that conversation with Vynn, decide that picking one side over the other isn't the answer, and that you'd rather find a different solution.
That's all there really is to it. Then, in Chapter 10 those three routes branch again based on the character you are closest to (so that would then be 15 routes in total you could end up on).