Lady_Zeb said it, she's an iffy author, you either love her or hate her really. I think you should read many different authors not just one, but research the author before buying because there is no real filter for 'new age' books. The book you picked up I have read bits of, and its a good one. I would avoid any other bool by Silver [with the exception of To Ride a Silver Broomstick] until you gain more knowledge. I know many people just starting out who got turned off as a result of something they learned/read in one of her books.
Bucklands Book of Witchcraft by Raymond Buckland [its a big blue book with a silver pentacle on it] or Wicca: a Guide for the Solitary Practitioner by Scott Cunningham are great books. I could list more but I don't know what you are interested in, your path, or how long you've been studying.