Answer: Read as you like, only it is desirable that these are real Kabbalistic books, for your level, and that you find yourself correctly in these books.
Question: What are the criteria for the correct study of the books?
Answer: Study the literature that is recommended to you in the Kabbalah courses in your community.
Question: Also, how do you work with books?
Answer: I have studied primary Kabbalistic sources in detail many times. There are even articles and letters that I have read a few hundred times, and every time I have found something new in them. Therefore, in Kabbalah, there are no sources that I would not have known and would not have worked through repeatedly, in the original language.
I read, underline, write out, compare, and look for specific similar material to somehow reveal it. This is the usual work of any researcher.
There are several variations of the work on primary sources. I often translate them, and if not, I start to abridge them, i.e., rewrite them in the original language, making the necessary adjustments.
The text that comes out is what I want to see now in my current state. Maybe next time, I will make a completely different summary from it.
Working on the texts, I can break them into paragraphs, give each paragraph a title, ask questions, give answers, etc. If required, I work through the text so that I am in it, and it is in me.
From the Kabbalah Lesson in Russian 3/25/18