Press F1 while VoiceAttack has focus to open VoiceAttackHelp.pdf in your default PDF viewer, which contains information on VoiceAttack's features.
Targeting can be performed using window title, process name, or window class.
Child windows can usually be targeted by commands, if they are normal (tool) windows.
The "Perform a Window Function" action uses a different targeting system than commands, and will generally only target top-level windows