Windows NT Command Line Syntax

Parameters    Command Line Parameters  %1  %~f1 
Variables     Creating and reading environment variables
Redirection   Spooling output to a file, piping input

Looping constructs
   IF THEN ELSE  Conditional Execution
   loops         Loops and Subroutines

Evaluating expressions
   Using brackets to Group and expand expressions
   SET /A        Environment variable arithmetic
   VarSubstring  Extract part of a variable (substring)
   VarSearch     Search & replace part of a variable
   Escape chars, delimiters and quotes
   Wildcards     Match multiple files

Batch Files for NT/2K/XP
   DateMath.zip  Add or subtract days from any date
   GetDate       Get todays date (any region, any OS)
   GetTime       Get the time now  
   DelOlder      Delete files more than n days old
   general advice Common Batch file problems 

Security
   NT Permissions Local vs Global workgroups
   WorkGroups    Built-In Users and Security Groups

Installation
   Services      List of Windows Services
   autoexec      Run commands at startup
   Recovery      The Recovery Console

Registry
   Windows XP Sanity Check
                 Turn off annoying WinXP user interface settings

For more examples see recommended books