To check the model of your printer simply look at the text above the screen or on the sticker on the back. To scan to a USB do the following:
1. Plug the USB stick into the front of the printer (The USB port is located under the start button shelf but above the paper tray.
2. Click the "Scan to" button (Top one on the left next to the screen).
3. Follow the options and click "ok".
4. Your documents will now scan to the USB. Only remove it once the printer has said its finished.