As A Man Thinketh
"As A Man Thinketh" contains some truly useful insights. It is beneficial to read it slowly because it is short, but packed with relevant ideas.
The book has been out for quite some time, and for this reason the language is a little dated. You can figure out the meanings and interpret them in current language. However, if up-to-date terminology is important to you, another Law of Attraction book might be a better choice.
It is helpful to read "As A Man Thinketh" several times over a period of a year or two, because the ideas and insights make more sense as you begin to use them. There are no exercises or examples (such as "Dan did this," etc.); the material is primarily theoretical. As such it can be dense and hard to follow. However, the basic gist of the material taught by the book is similar to that of more current Law of Attraction texts, minus the examples and workbook-type exercises.
The book is well worth reading, and it is a good choice to purchase because it it short enough to reread numerous times without a large time commitment.