Just started learning numerology? Whose book should I read? How's Li Hanchen?

You need to read the Book of Changes before learning the eight characters. The first book you read when you are mature is Zi Ping Zhen Quan, then Yuan Hai Zi Ping, and finally Sansheng Zonghui. Books written by modern people, especially those written by the new school, must not be read, nor can Ren Tieqiao, Xu and Liang Xiangrun, which is too misleading. As for the Li Hanchen you mentioned, needless to say, polytheism, falsehood, falsification and so on. It's all lies, even he changed it over and over again. Just look at the ancient books.