Tantra is an ancient and well-documented practice that originated in India thousands of years ago. At that time it was not a "practice" but a way of life. It has a fascinating history, and if you are interested in learning more about it, there is a ton of information that is available on the web.
I'm more interested in how it relates to you as an individual, and how you can apply it to your life in a way that is effective, pleasurable, and above all, practical. Just to give you some context, think of the highly-popular practice of yoga. Many swear by yoga as an exercise that keeps you in optimal physical condition. They go to a class a few times a week and flaunt a newfound level of flexibility and movement. Then there are Yogis, for whom it is a way of life. They practice daily, meditate, swear off meat and ego, and claim benefits far beyond improved posture and a hard ass--like serenity and heightened awareness. Nonetheless, both reap benefits--and embracing the physical doesn't eradicate the spiritual aspect and vice versa.
Tantra is similar in the sense that you can use it to master your technique as a lover, or embrace a rich spiritual path that is exciting, enlightening, blissful, deep, sexy and sacred. Tantra is fueled by sexual energy because the entire Universe is fueled by sexual energy, but it not "about" sex any more than sex is "about" your genitals. The map is not the territory.
The intention of Tantra is to awaken your sexual energy to its full potential-because it is the primary source that directs all other aspects of your life. Most of us, male and female, have been greatly cheated of that gift. Most of our sexual conditioning in this society has been tainted with shame, guilt, and religion...which affects our ability to have pleasure on many more levels than we are conscious of. Much of our ability to be intimate in the first place is blocked for years by a build up of fear, anger, and mistrust from past relationships.
The Tantric philosophy is rooted in acceptance--of your body, your experiences, your thoughts, and your feelings--without judgment. It's the art of getting into agreement with yourself--of honoring where you are, right now, in order to get to where you want to be: closer to your happiest, most powerful self. From this place of surrender comes access to your highest power--the reclamation of your sexual energy as pure, creative Life-force.