Sexual positions, acts and more...
Here are some sites that go into elaborate detail on every topic... including galleries of positions

• Sexuality.org - full and comprehensive guides - anal sex, BDSM, positions you name it they have tips
• Sex Tips 101 - Alternative Sex, Foreplay, Kama Sutra, Know Your Body, Improving Sex, Intercourse, Pleasing Men, Pleasing Women, Positions, Relationships, Using Sex Toys