Android key generation page is not clear

[cronoklee]

On the page Signing Overview > Android
"2. Set Java_Home directory."

This is not clear. Set Java_home to what? The page linked describes installing JDK but JDK is not mentioned anywhere in the PhoneGap instructions. This is a large application which seems wasted just to get a signing key. Is it required?

Additionally, on step 3, there is a dollar sign prepending the command, however windows does not use or accept dollar signs at the beginning of commands.