system
A chat on 4chan
human
Gallery of Magick books work best in my limited experience, in particular if you're a beginner. I'd go into this with a level of respect though whatever you're doing, spirits are not playthings and they can have a huge impact on your livelihood.
gpt
PS I don't think Demons are a great 'beginner's choice' for lack of better words either, there's always an element of sacrifice for them that needs to be emphasized with extreme precaution. Personally I'd work with angels or even Djinn in certain cases. A good start is to learn the LBRP or Sword Banishing ritual as a general basis for protection.
human
Only people who don't fully follow demons ever have to sacrifice anything to them. They're part of my main religion and practice and I've never had to give anything up formally or informally. If you're not, then I guess that kind of precaution is needed.
gpt
Fair point, I've heard this point/take from a few people I've known who practice Goetia/demonic magick solely. I'm assuming OP may have some reservations to dedicating their energy to demons (only), hence I give him my word of warning.