I want to read some primary sources from the European middle ages on magic. Good magic, evil magic, alchemy, spells. I'm especially interested in manuscripts that are like instruction manuals, teaching you how to do magic, if those exist. Can anyone point me in the right direction?
Do you, by any bizarre chance, live in the UK? Because on the 20th of October this year the British Library in London will exhibit a large collection of exactly the type of manuscripts you're looking for (officially it's a Harry Potter exhibition).
If not, the exhibition's website already mentions some of the items on display. A great starting point for your research!