The same way you would with any other PC. If you connect to a PC with the file via USB, once connected, take a look at the DROID's "notification bar".

 

Snooz48;

You can use multiple methods to get the file onto your Droid:

- receive it in email
- copy it to the SD card manually
- mount your Droid on your computer and copy the file over

Hope this helps,
Scott