Wormbase (www.wormbase.org; General database for C. elegans)

Wormatlas (www.wormatlas.org; C. elegans anatomy site)

Wormbook (www.wormbook.org; A collection of reviews in the C. elegans field)

Neurotransmitter identity map (three papers from the Hobert lab mapped the neurotransmitter identity of the                                                        C. elegans nervous system)

Cell fate regulator map (Hobert, 2016, WIREs Dev Biol): 

OrthoList (http://ortholist.shaye-lab.org/; finding orthologs between C. elegans and humans)

Worm wiring (http://wormweb.org/neuralnet#c=ADA&m=1)