Ok,so it's 32 bit.
We can do it two ways,you can download the tar.gz package and follow these instructions:
Bear in mind this is for iceweasel.
Installation instructions for tar.gz
1. Click the download link to begin installation. A dialog box will appear asking you where to save the file.
2. Save the .tar.gz file to your desktop and wait for the file to download completely.
3. Unpackage the file. A directory called install_flash_player_10_linux will be created.
4. In terminal, navigate to this directory and type ./flashplayer-installer to run the installer. Click Enter. The installer will instruct you to shut down your browser(s).
5. Once the installation is complete, the plug-in will be installed in your Mozilla browser. To verify, launch Mozilla and choose Help > About Plug-ins from the browser menu.
Or alternatively you can add the Debian multimedia repository to your apt sources.
Then simply install it with aptitude install flashplayer-mozilla
The choice is yours.
Post back if you need more help.