JH (Herbie) Brennan is perhaps better know for his fantasy fiction work but has written several good books on the Occult and Magic.  This book seems to be out of print now but is worth trying to find a pre-loved copy.

On the astral plane the magician can experience visions of Time Past and Time to Come and will come face to face with gods and demons, angels and elementals.
In this book a highly regarded contemporary occultist reveals the true nature of this universe of limitless possibilities within each one of us.
Astral Doorways, through a series of concentration and visualization exercises, provides a safe and effective key to this boundless world.
A classic.

Out of stock