There are two published books that teach Lojban; The Complete Lojban Language and What is Lojban?. There is also an incomplete but substantial guide, Lojban for Beginners, which teaches Lojban as a course.
The Complete Lojban Language is a complete description of the artificial language Lojban. It serves as a reference grammar for the language, offering an overview of the language, as well as linguistic details on every aspect of the language. This book serves as the standard defining the language design. That design has been declared frozen for a minimum 5 year period; anyone who learns the language from this book can be assured that it will not be continually changing. Though this description may sound imposing, technical and formal, the book is written in a light, often humorous style that teaches the reader about the Lojban language, about logic, and about linguistics in general.
An online version of The CLL called The Lojban Reference Grammar is available. A list of errata is also available. Most of the errata have been approved.
What is Lojban? is intended as a concise introduction to Lojban, providing a taste of the language for those who may decide to take an interest in it.
Lojban for Beginners is an introductory course on Lojban, consisting of fifteen lessons. It has been authored by Robin Turner and Nick Nicholas, and gives a gentle introduction to the structure of the language. Robin authored lessons 1–8 and 10–11 in 1999; Nick added to the existing lessons, and authored lessons 9 and 12–15, in 2001. This book is very accessible, and interacts with the reader using relevant exercises!
There is also a PDF version here: Lojban for Beginners PDF And there is a PDF Chinese version:逻辑语入门
The errata for this book lives on this page.
ld.pdf is a Lojban-English and English-Lojban dictionary. This PDF version has some nice additions to the run-of-the-mill dictionary:
Lojban Dictionary.pdf is the same as ld.pdf except that AmberShadow has added bookmarks for your navigating pleasure. It also appears to be about half the size in megabytes for no apparent reason. Current version: Edition 8
Seth Lojban Dictionary.pdf is a file designed for print-on-demand machines like the one on BYU campus. Seth Lojban Dictionary Cover.pdf is the book's cover, in similar style to my printable version of LFB. POD machines often require the cover and book to be separate files. The dictionary itself is simply the standard word lists put into a very friend format (no lujvo and such, because of the incomplete nature of such a list). I have used it for a few months and liked it enough to put up for anyone's use. I can also arrange for printed versions of it to be available if there is a desire.
The Lojban Wave Lessons are a set of online lessons created by kribacr and a community of other Lojbanists that employ newer methods of teaching, including teaching the use of terminators as obligatory for the first several lessons and teaching xorlo and dotside as the normal rules. This is preferred over L4B or CLL by some students and recommended by several teachers as it teaches early on several key concepts which prevent confusion later on.