I hear alot of people on the NET asking about "credible sources" and "what books should I read" and "how do I become a witch". Pretty much I have been answering everyone the same. Different interpretations will continue to abound both in written materials and in any teachings that you may encounter. There will NEVER be only One Way of practicing Witchcraft. Get used to it. No one has the "one true answer"...and any teacher, High Priest or Priestess worth his or her salt will tell you this up front. If they don't - RUN FAST!!!
1) Learn to ask SPECIFIC questions of other Witches or Pagans when you need help. And ask yourself some questions, too. "What do I think Witchcraft is? What do I find here that has meaning for me?"
2) Tell the truth. Can seasoned Witches tell if someone is "full of it"? Yes, they can and rather quickly, too! Be honest about what you know and what you don't.
3) Learn something every day, no matter how insignificant or profound. Read as many books as you can on History, Myths, Poetry, Psychology and Science as well as books on Witchcraft or Magick.
4) THINK... ponder... reflect. No one else can or will learn the lessons for which you have chosen this life. YOU are your own teacher and healer. This is your life. Live it well.
5) Witchcraft is NOT the ultimate anwser. It is NOT a easy trip to power. It is NOT a head game without responsibilities. If you are looking something along these lines you are probably wasting your time and that of others. If you ARE interested in learning about yourself, about nature, and the spirituality inherent in the Multiverse, then you ARE on the right track.
The above (although I edited it rather heavily) and more can be found at The Witches' Voice. Everything you need to know is in your self, but The Witches' Voice is a good place to start. Another GREAT site is Gwenivere's The Enchanted World of Whtwicca.
Here is a reading list that I hope will be helpful, but try to read everything that you can get your hands on. As for the Scott Cunningham books, they have gotten a bad rep as being sugary sweet. Well, this IS a Beginner's list of books. I say let them enjoy their innocence. They just need to know at this stage that for every Yin, there is a Yang.
Margot Adler "Drawing Down the Moon "
Scott Cunningham "Wicca: A Guide for the Solitary Practitioner "
Scott Cunningham "Wicca: A Further Guide For the Solitary Practitioner "
"The Farmers Almanac" (A great book for following the phases of the moon)
May the Goddess and God guide you in your path.