Metu Neter 1 and 2 are good introductions to Kmt. However, as you learn more, you will realize that some of Ra Un Nefer Amen's interpretations are incorrect and others are based upon a mixture of Far Eastern (Indian) religions and practices. To be fair, Ra Un Nefer Amen says on his website that his religion is a mixture of Caanan, Indus-Kush, and Kemetic beliefs. It's a good start. He gives a good description of Kemetic meditation in both books.

My website should be up and running in about a month. One of the services we will be offering are correspondence courses in Kemetic Spirituality. Not just the significance of the statues and the Mtu Ntr, but also how to incorporate the practices and philosophies into your everyday life in the same way that our ancestors there did. I managed to find a very reliable importer of all of the things that one would need to perform prayers, offerings, and ceremonies, including some very choice Somalian Frankincense resin and powder and Ethiopian damar.