be prepared for a cacophony of different points of view. Asking the question you asked, you won't get just one straight answer.
Personally I use the suttas to guide me. Physical teachers can be very helpful in clarifying difficult issues in the suttas. But sometimes teachers, despite the best of intentions, can give instructions that simply do not accord with what the pali suttas actually say.
I find the 'Samaññaphala Sutta: The Fruits of the Contemplative Life' very helpful http://www.accesstoinsight.org/tipitaka ... .than.html
also (of course) other suttas such as the Mahasatipatthana sutta, Anapanasati sutta, and the Kayagata-sati Sutta, to name a few important ones.
I compare what these suttas say with actual meditation experiences, as well as with each other, The meaning of a sutta is revealed over time, by repeated study and testing in the light of one's own experiences, I have found.