I tried to find the same info in english, without success. However, here is a short summary of the dutch text:
+ make sure both lovers are ok with trying anal intercourse and are experienced and know/feel what the other lover wants/needs
+ the anal entrance must be stretched out in the beginning step by step, until the penis fits in; it is best to use fingers first (for example, postpone real penetration until the male's birthday)
+ make sure the penis, the anus are clean and the rectum is empty
+ never have vaginal intercourse after anal intercourse, because the bacteria in the rectum may cause vaginal infections (anal after vaginal is ok though)
+ it is important to use either lube, saliva or (even better) vaginal fluids to make the penis slide in easily
+ work your way towards anal intercourse, take your time and don't do anything you don't like (yet)
Ok kids, that's all for now. Take care of yourself, and eachother.