It goes without saying that this book exists to be a source of information and assistance for Subversion users new and old. Conveniently, though, the Subversion command-line is self-documenting, alleviating the need to grab a book off the shelf (wooden, virtual, or otherwise). The svn help command is your gateway to that built-in documentation:

$ svn help
Subversion command-line client, version 1.6.13.
Type 'svn help <subcommand>' for help on a specific subcommand.
Type 'svn --version' to see the program version and RA modules
  or 'svn --version --quiet' to see just the version number.

Most subcommands take file and/or directory arguments, recursing
on the directories.  If no arguments are supplied to such a
command, it recurses on the current directory (inclusive) by default.

Available subcommands:
   add
   blame (praise, annotate, ann)
   cat
…

As described in the previous output, you can ask for help on a particular subcommand by running svn help SUBCOMMAND. Subversion will respond with the full usage message for that subcommand, including its syntax, options, and behavior:

$ svn help help
help (?, h): Describe the usage of this program or its subcommands.
usage: help [SUBCOMMAND...]

Global options:
  --username ARG           : specify a username ARG
  --password ARG           : specify a password ARG
…

Many Unix-based distributions of Subversion include manual pages of the sort that can be invoked using the man program, but those tend to carry only pointers to other sources of real help, such as the project's website and to the website which hosts this book. Also, several companies offer Subversion help and support, too, usually via a mixture of web-based discussion forums and fee-based consulting. And of course, the Internet holds a decade's worth of Subversion-related discussions just begging to be located by your favorite search engine. Subversion help is never too far away.