Hello Sara,
Welcome aboard the AYP site. I think that if you stay with us for a short time that you will be hooked, as Yogani has layed out an extremely comprehensive program for spiritual growth.
The Tantric path involves cultivating and preserving sexual energies to facilitate spiritual growth. The gist is to excite your sexual energies and prolong them without orgasmic relief. Now this is tricky at first but in the long run it is very pleasurable. Sexual energies as you may know are very powerful (they create or procreate life) and are the same energies that faciliate enlightenment. I suggest that you read the Tantric links in Yoganis lessons. Here is an introduction
http://www.aypsite.com/plus/T1.html Now I am a male and I understand the masculine aspect of losing energy through orgasm. We are encouraged to have orgasm no more than once a week. I am not really familiar with the female aspect. I assume it is similar. Perhaps some of the ladies can chime in with their experience. I know that orgasm depletes a good portion of my inner energies for a day or so.
One nice way to bring up sexual energies with little effort is to practice AYP. The sitting style that is recommended is called siddhasana. This is sitting with one heel of the foot pressed against the perinium which is the soft spot located between the genitals and the anus. This slight pressure from the heel helps generate preorgasmic sexual energies to enhance the meditation experience.
As for prolonging orgasm during sexual activity to conserve energy, you may just need to back off momentarily prior to orgasm to allow things to settle down. An understanding partner is critical in this. Again, I cannot speak for women and what their experiences are but as a male, stopping short of orgasm is profound. We can have multiple inner orgasms without emmision and remain energized afterward instead of falling asleep depleted. These inner energies help to purify the nervous system and condition it for spiritual growth.
I wish you the best of luck and hope that you give AYP a shot. It has changed my life immensely.
With Peace and Respect,
Paul