Roughly in order of difficulty, starting with the easiest:

  • Female Deities in Buddhism or Meeting the Buddhas, by Vessantara.
  • The Heart of Understanding, by Thich Naht Hanh
  • Wisdom Beyond Words, by Sangharakshita
  • The Heart Sutra: The Womb of Buddhas, by Red Pine
  • Mother of the Buddhas: Meditations on the Prajnaparamita Sutra, by Lex Hixon