[Nick]

Yes, Carlos Castaneda did not invent the Toltec teachings. He re-introduced them to the people of the west. Before the rise to power of the patriarchal religions we all had access to this knowledge. The Christian church has been particularly brutal in the way that it has suppressed this knowledge. Over the centuries millions of its own people have been put to death for daring to practice the old ways, and all written accounts have been destroyed. Through propaganda they have succeeded in labelling this way of life satanic and evil.
The native people of this world are to be admired for keeping this knowledge alive, but it is not their exclusive property. Even without their help we can re-discover this knowledge by spending time alone in nature. The Earth is a living being, she can teach us much, and is willing to do so. Centuries of persecution and indoctrination mean that we do not even think of going on a vision quest any more.
With regard to reading other authors of Toltec wisdom, I believe it is good to do so. Different people will emphasise different aspects. For example, Ken Eagle Feather writes a lot about energy and its many manifestations, Theun Mares and Victor Sanchez concentrate more on practical applications of stalking and not-doing, whilst Carlos Castaneda has a more mystical bent of character and concentrates a lot on dreaming. By sticking to just one "guru" we may run the risk of making our assemblage points more rigid.