Wormbase: a database containing detailed information on individual worm genes
Wormatlas: a detailed description of C. elegans anatomy
C. elegans II: the online version of a book containing review chapters on all areas of C. elegans research. Contains an introductory chapter as well. Note: does not reflect the the current state of knowledge due to its publication date (1997).
WormBook: a collection of open-access review articles on current research with C. elegans. Essentially a continuation of C. elegans II.
White et al. paper describing the electron microscopic reconstruction of the C. elegans nervous system)