If you've got a valid ISO file then burning it to a DVD and booting from it should work just fine.
Note however, that you can't just put burn the ISO onto the DVD as a file - you have to use your burning software's "Image" option to burn it (at least that's what Nero calls it). If you end up with a DVD that you look at with Explorer and see the ".ISO" file on it, you've done it the WRONG way.
Yes. I have done it the wrong way ... I will redo this step and repost results.