The AAVSO Manual for Visual Observing of Variable Stars (ISBN 978-1-878174-00-0) is a comprehensive guide to variable star observing. Included is a lot of information and tips on how to make variable star observations and report them to the AAVSO. The Manual is available online in .pdf format. Translations of the Manual are available in several languages.
This translation would not have been possible without the hard work and dedication of volunteers Fatemeh Bahrani and her colleagues, Ali Honarmand, Fateme Kayanikhoo, Mozhde Mohamadi, Sajad Safari, and Arezoo Saleki of theDr. Hesabi Institute in Shiraz, Iran (http://www.dr-hesabi.org).
Thanks to the hard work, dedication, and persistence(!) of AAVSO member/observer Péter Molnár and Dr. László Kiss, the January 2010 edition of the "Manual for Visual Observing of Variable Stars" is now available in Hungarian.
Thanks to the efforts of Cheng Simiao, a young and very enthusiastic observer from Beijing, we now have a new, more up-to-date Chinese version of the "Manual for Visual Observing of Variable Stars" available for download. He wishes that this edition be thought of as a 100th birthday present to the AAVSO as well as an 18th birthday gift to himself.