Firefox Plugin HOWTO

How to install various plugins for Firefox

cd
tar xvzf /pub/downloads/install_flash_player_7_linux.tar.gz
cd install_flash_player_7_linux
./flash_installer and follow the instructions 

Install per user.

Install the java package

apt-get install java-package

Create the Java deb package

fakeroot make-jpkg jre-1_5_0_01-linux-i586.bin

Move the resulting debian package to `/pub/debian/local` and rebuild the package list.

Install.

More information can be found here