While there are numerous books about creating rituals for group use, and others on how to form, organize, and operate covens, this is the first to discuss working magic in a group (of two or more people). Spellworking for Covens addresses raising and sending energy as a group, the power of the group mind, traditional ritual structure, and several types of spells.
To make it even more practical, this book also provides a grimoire containing texts and instructions for actual spells that can be worked within the group setting.