Originally named after a group of verses in the spiritual literature of Asia, Tantra has far outgrown both Asia and religion itself, to become one of the basic 'approaches' to life in the body and the spirit as well.
While there are thousands of pages written already on the topic, the basic PREMISE of Tantra bears repeating; that..
We have all experienced Tantra throughout our lives, perhaps without realizing it was occuring. As infants, we absorbed the traits of our parents by Tantric "reflection:" later, we did the same with our playmates, hero-figures, friends and ESPECIALLY our Lovers. Tantra's first and most lasting Principle is that it operates on LOVE. Whatever we Love, we melt-into.. and anything we do NOT love, we do not Tantra-with but EXCLUDE FROM OURSELVES, or DISOWN. The second Principle of Tantra is that anything that we wrongfully disown is drawn to us, to seek reunion. This powerful teaching deserves a second (and third!,) thought!
Are you surrounded by the types of people and life-experiences that you Love?.. or are you surrounded by A FEW of your Beloved things and friends and A LOT OF OPPOSITES TO THAT? Tantra begins it's study by asking us to honestly answer that question.. and then DO SOMETHING TO IMPROVE OUR RELATIONSHIP WITH LIFE.
How we go-about the process of improving our relationship with Life is by recognizing the two "categories" Life presents to us: 1) THE BELOVED things and people we 'melt-into' and.. 2) THOSE THAT WE DO NOT LOVE sufficiently, and therefore are surrounded-by like an Army of 'problems' and 'enemies.'
BOTH of those categories Tantra calls 'THE MIRROR;' one 'side' of which we "Love" and the other 'side' of which we simply DO NOT "SEE" OURSELF AS. Tantric Relating is the process of learning to SEE oneself as and in all of BOTH SIDES of our Reality.. until we have 'melted-into' everything in our lives. It is the claim of Tantrists that this process leads to genuine PEACE and a Universality of nature that makes one truly 'the brother (AND sister) of ALL PEOPLES.'
Compare the two lists.. and try to imagine ways of learning to 'melt-into' the second list, and make peace with it. Tantra teaches that doing so will naturally make that second list more enjoyable for you while also diminishing it's tendency to be EVERYWHERE for you to confront. In short; this should make your first list more available to you.
Interestingly enough, the third Principle of Tantra is that; once you have removed the "judgement" against both sides of the human mirror, YOU WILL BEGIN TO SEE "BEYOND" THE HUMAN WORLD.. into the World of "the gods."
One of the most common beginning-points for Tantric studies is the basic fact that our species is divided into TWO GENDERS. Sexuality and how it grows is an essential part of this science. For instance: if you are a Man, you may "Love" Women and spend much of your time competing with other Men for Women's attention. THOSE ARE THE TWO "SIDES" OF YOUR MIRROR. Tantra advises you to find a more Universal view of reality; and learn to 'melt-into' your fellow man. not only will this broaden your self-understanding, it will also make you far more enjoyable for BOTH genders to be around. If you happen to be a homosexual, you may think yourself already "past" all such mirror-opposites; yet you, too, may be surrounded by DIS-similar lifestyles that trouble you and detract from your self-definition and happiness.. and THAT is YOUR Two-Sided Mirror.
SEXUAL TANTRA begins with learning to LOVE whatever you Love, while still also Loving everyone ELSE enough to let-down your barriers, and 'melt' into them as "similars." SURE, THIS WILL CHANGE YOU! Whatever you melt-into "rubs-off" on you. But it ALSO 'disarms' things that may have previously really BOTHERED or HURT you. Being willing to out-grow our Barriers is crucial to Tantric Self-Union.
Many people come to Tantric studies expecting (or at least HOPING!,) to find something similar to 'the Kama Sutra;' a graphic, detailed and "permanent" form of sexual liberty which will serve them as a sort of 'approved' harem. WELL AND GOOD! Certainly Tantra CAN begin that way.. and frequently does. But Tantra means "melting together:" and sooner or later, one discovers that one is becoming very much "like" the objects of one's original desires. Having spent enough time in their Tantric Embrace, one has both 'rubbed-off' on one's Lovers (making them somehow slightly less 'desireable' in many cases,) AND they have rubbed-off on YOU (making you considerably less "like" your former self-opinion.) Tantra is NOT a "permanent" sexual relationship.. but a permanent SPIRITUAL relationship, between oneself and the rest of Life.. a relationship learned through 'rubbing-off' on each other until truly "at one" with them. In the long run, Sex is a PERSONAL way of having pleasure; Relating is (at best) a PLEASURABLE way of having People around. Learning how to balance this into non-"ownership" and "expectation"-free LOVING of all people's freedom is the life's work of every Tantrist.
Those who have accomplished this remarkable 'balancing act' of unifying not only both sexual genders but oneself and one's Beloved into a 'new' lifestyle of Tantric Unity are no longer purely 'human' personalities, but something far more vast and lasting than that. Asian philosophies call this Unified Self "ISHVARA."
DIVINE TANTRA emerges within us when we have 'cleaned our Mirror' through improved sexual and relationship skills enough to allow the 'god' within each person to be glimpsed. As we improve our clarity and ability to "see through" all humanity to the spirit within, we begin to Tantra with GOD.. and our definition (and EXPERIENCE) of reality is massively expanded. Tantrists experience "God" as THE BELOVED hidden within all of Life, and waiting only for us to grow strong-enough to meet 'him' (AND her!,) in the mirror of our own passions and pleasures.
Those who do not yet realize that there really IS something 'sacred' in the Universe, have simply never yet LOVED deeply-enough; for Love is the seed from which spirituality and divinity grow. Those who do not yet know how to Love also do not yet know ANYTHING 'sacred;' and those who DO Love ARE themselves sacred.. and see that in all others as well.
You do not need a 'Teacher' or 'manual' to teach you about Tantra. Hearing the basic Premise and Principles is itself quite enough to stimulate the Tantric process. However, since there ARE many well-documented challenges, phases and details within the Tantric Path, you might find it helpful to have a support-system to help with those details. One fine bit of advice in selecting a Teacher might be; SELECT SOMEONE WHO IS PART OF WHAT YOU ALREADY LOVE. Someone of your own current sexual preference and lifestyle is a generally good idea.