Tara's Enlightened Activity - An Oral Commentary on the Twenty-One Praises to Tara — by Palden Sherab and Tsewang Dongyal
Includes lots of advice on how to do the Tara practices by two exemplary Nyingma teachers.
The Cult of Tara - Magic and Ritual in Tibet by Stephan Beyer
This work presents and interprets the living ritual of Tibetan Buddhists.
The Practice of Green Tara — by Bardor Tulku Rinpoche
This teaching is on the deity called Arya Tara. Often known as the great liberator who rescues beings from the eight great fears. She is one the bodhisattvas that Avalokiteshvara created from a drop of his tear.