The works of; John Woodroffe (pseudonym: Arthur Avalon) gave an important overview of Bengali Tantra. Perhaps his most influential work is The Serpent Power, which is on the subject of the so-called Kundalini-Shakti, the latent psycho-spiritual power which according to Tantric philosophy lies dormant at the base of the spine but can be awakened through specific Hatha Yoga exercises.
Just as there are Vaishnuite and Shaivite Guru-sects, so there are Shaktic ones. I might mention the "Sahaja-Yoga" movement of Nirmala Mataji, which promises its followers instant and spontaneous "self-realisation". My own experience with this sect has convinced me such claims are over-enthusiastic to say the least!.