Here I will start to tackle the mammoth subject of deities. The first thing that I want to say is that working with deities is not necessary to witchcraft. The next I will say is that you don’t need a patron deity, this is an idea that has come en vogue. You also don’t need to work with only one deity ever.
So the first thing to understand is that there are various pantheons within mythology; Greek, Roman, Norse, Celtic, Egyptian, Catholic, Judaic, Aboriginal, First Nations, Hawaiian, Hindu, Chinese, the list really does go on. The Greek and Roman pantheons are parallel, meaning that in most cases there is a very similar god/goddess with very similar mythology within each. Broadly these are referred to as Classical Mythology as their stories are embedded within our society even if we don’t notice it. Just think about Lady Justice (Themis) and how she is synonymous with law and order, as well as our justice system.
Another thing is that there are gods/goddesses who come into fashion because of pop culture. We have seen this in the rise of popularity of Hecate, Loki, Thor, Diana and Papa Legba. Their popularity isn’t a bad thing by any means, but before committing to work with a deity you need to understand their essence so you know what their energy is. For example both Papa Legba and Hecate are liminal deities, they are quite literally gateway deities and will assist in facilitating opening roads, unlocking doors and connecting you to other spirits, realms or deities. Many people mistake their appearance as a personal connection, when really they are passing on a message on behalf of another deity. Loki is a trickster, so this is something to keep in mind when working with him.
I want to advise practitioners to work with deities within the same pantheon with few exceptions. There is logic here which I will explain. Pantheons are linked to cultural practices and customs, and while there is nothing wrong with working with a foreign pantheon, you need to understand that you increase your chances of offending deities. I’m certainly not suggesting that deities aren’t multi cultural, but if you push two deities together without understanding their relationship, you increase the chances of them not helping you out. You cannot work with a Hindu deity without understanding dharma and karma in the Hindu sense, it would be entirely arrogant to approach a Hindu deity with the wrong offerings and then ask them to work with a deity they don’t know (or worse don’t like) from another pantheon.
On that same vein, do not make deities share an altar or space for your worship without doing your research. If we are talking the Greek pantheon, I wouldn’t make Hera share an altar with any deity that wasn’t a Olympic god or goddess. But Demeter, Persephone, Hecate and Themis would happily share space. When you make them share worship when they don’t get along you are inviting trouble and their wrath.
You don’t need a god and a goddess. you can work with two gods, two goddesses, or just one. You don’t need to balance masculine and feminine energy within your practice. I think that idea is bit antiquated. Your own energy and gender shouldn’t stop you from petitioning a deity of a different gender energy.
I also want to add that it is a good idea to be researched in your chosen pantheon, this is something that we learn from and continually evolve from. For me being intrinsically connected to the Greek pantheon, the use of olives, olive oil and olive leaves an wood feels like a natural connection. This is further supplemented by my studies of literature, history and philosophy; even the great Socrates visited the Oracle of Delphi for advice and prophecy. But my enjoyment of Greek mythology doesn’t stop me from delving into other mythologies to better understand how witchcraft and folk magic fits into everything.
For reading, there are many great books. I love Stephen Fry’s collection (Mythos, Heroes, and Troy) for a summation of the Greek myths. I also have Classical Mythology A-Z on hand, as well as copies of the Iliad and the Odyssey by Homer. Another fantastic book from my childhood is The Encyclopaedia of Mythology by Arthur Cotterell. I do also recommend owning a copy of the Holy Bible so that some of the stories can be read and interpreted, but that isn’t for everyone.