This may be the most clear, consise and complete meditation instruction booklet in existence.
Do not let its small size and low price mislead you -- Yogani has put a lot of great work into making it small and accessible.
The meditation technique taught inside it is at once one of the simplest as well as one of the most powerful for producing spiritual transformation. It was used by the sages of India throughout the ages, and also in various monastries and spiritual communities throughout the world, including some of the Desert Fathers of early Christianity. It was brought into some prominence in the West by Sivananda and others over the last century.
Yogani teaches it expertly. Read every word with care.
Whether you are new to meditation, or have meditated before in which case it will be great review, read it, follow the practice, and read it again occasionally. Like its author, it will be a gentle, unassuming, but very powerful guide.