The Elk Code Manual is available, as is a manual for the Spacegroup utility. You can ask and answer questions in the Elk forums on SourceForge.net. A mailing list is available for notification of new releases, features and bugs in the code. There is also a collection of useful links. Online lectures and presentation notes from the CECAM Elk Tutorial by experts in DFT and many-body theory can be found here.
Vitaliy Romaka has produced some very nice Elk tutorials complete with video demonstrations.
Citation of Elk
Citation of the code is not mandatory but would be appreciated by the contributors - a reference to this website will suffice (cite as: J. K. Dewhurst et al. elk.sourceforge.net). We also recommend that the input files used be made available to other researchers.