A Book of Shadows is something every real witch has. It is the book of reference where all magickal information, spells, and formulas are written by the owner. It is one of the most important tools. It is also known as a grimoire. The content may vary from witch to witch.
Crystals are used to attract positive energies and also to recharge psychic energy. Some Wiccans for example base the use of crystals on chakras. Chakras are points of the body where energy is centered. There are seven main chakras. Chakras are connected with crystals. Crystals are used to balance, open and heal these energies in the body. Crystals energy can be used with jewelry, meditation or also pendulums(even though pendulums are used more for divination or healing).
Every crystal helps with a specific type of energy. For example, clear quartz attracts positive energy and black tourmaline traps negative energy so that it doesn't harm you. Larimar, my favorite, is a symbol of the Dominican Republic. This beautiful stone contains energy that helps to find peace and tranquility for the body and soul. It transmits pure spiritual substance into chakras which will help you find your path in life.
Magick is a subject with a lot of informational categories, to truly understand the meaning of almost every single one of them it is required to really connect to it and experience with devotion this path. It requires energy, time and will.