SHELX wikis and manuals

Brief summaries and lists of keywords may be found in the following:
SHELXT - Small molecule (SM) structure solution
SHELXS - Classical SM direct methods
SHELXD - SM direct methods and zipped test data
SHELXC - Preparing files for MM structure solution with SHELXD and SHELXE
SHELXD - MM (macromolecular) substructure solution
SHELXE - MM phasing
SHELXL - User guide for SM structure refinement (PDF) and zipped test data
SHELXL - Alphabetical list of instructions for structure refinement (PDF)
SHELXL - Command list (HTML version based on contribution by Lee Daniels)
CIFTAB, ShredCIF and zipped CIFTAB templates
AnoDe - Anomalous Density analysis (MM)

Kay Diederich's CCP4 wiki also describes the use of SHELX:
MM Phasing with SHELXC/D/E
MM Refinement with SHELXL

See also the book edited by Peter Müller on SM refinement with SHELXL and the book on SM SHELXL refinement in Japanese by Shigeru Ohba and Hidehiro Uekusa.

For historical interest the SHELX-97 manual may be consulted (PDF)