I don't know of any books but I can tell you my experiences...... I used to be cold all the time, now I'm hot most of the time. Now I wear short sleeves in the winter too. I can't wear flannel to bed, I wake up sweating. Last month my period lasted 9 days...what is that all about??? I know that everything starts changing. Your periods may get closer together, or further apart. They may be shorter in duration or they may last longer (like 9 days). As usual, we just have to go with the flow...if you know what I mean.