I've been meaning to read this ever since the Channel 4 adaptation in 1993, which starred Olympia Dukakis and Laura Linney.
The novel was first published in 1978 after being serialised in the San Francisco Chronicle. In it Armistead Maupin captures the spirit and atmosphere of a society with liberal attitudes to sex, sexuality and drugs. As such, the book does not seem as dated as it might have done.
The book follows the stories of around eight archetypal characters, from the naïve Mary Ann to the wise (but mysterious) Mrs Madrigal, the openly and flamboyantly gay (Michael) to the secretive and sinister (Norman). Centred on the lodgings run by Mrs Madrigal, and the "family" of residents, this is a book about friendship, relationships and the (often unexpected) connections between people.
While some of the references may be dated and specific to San Francisco, the book is a joy to read. The short chapters and easy-going style make it eminently readable.