This page explains how to save the credentials for the tools in configuration files instead of using them on the command line every time.
This page lists a number of options that may be used.
This page describes the Decred block header.
The official Decred releases have signed hashes that you should check to confirm that they are the same binaries that the developers posted. This page provides instructions for that.
This page shows how to delete your local wallet.
This page provides some examples of things on can do with dcrctl.