You will need a .msha manifest file to install your .mshc help file. The .msha manifest is an XML file containing some basic installation instructions, including the name of the .mshc help file(s) to install.
To install help we pass the .msha manifest file to HelpLibManager.exe along with the .mshc help file(s).
In both MS Help Viewer 1.0 (VS 2010 help) and Help Viewer 2.0 (VS 2012 help) all registered help is copied into a central content store.
For more information on MS Help Viewer see http://kb.helpwaregroup.com/ms-help-viewer/hvinfo
Note that HV 1.x and HV2.x have the same help file format, however they have different executables/runtime files.
Help is installed by the book. Each book can contain one or more packages. A package is either a .mshc help file, or a signed .cab file that contains a single .mshc help file (with or without a .mshi index file).
Note: Microsoft .cab files contain a .mshc and a pre-compiled .mshi index file. Cab files can be signed and installed silently. For HV 1.x Microsoft have no mechanism for helping you to creating an index file. Although you can probably just copy one out of the Help Library data store. See Add an Index to your .Cab Help Package.
For Help Viewer 2.x (VS 2012 help+) there is now a new utility HelpIndexer.exe that allows you to create HV 2.x index files.