I've been following this guide and I've done everything up until the sudo command bit and the only thing I have actually changed is doing /rdisk2/ instead of /disk2/ as it allows for much faster writing.
Whenever I try and put it into the PC it doesn't recognize the drive as having a boot device on there
That article was written for the downloadable public beta release of Win 7. I doubt it will work for the official retail release. By far the easiest thing to do is purchase a full version retail copy of Win 7 on DVD.