Don't feel embarrassed - I actually had the same problem for quite a while. I think PTC/ThingWorx are moving around between a couple community/support sites and some things aren't as easily accessible as they probably should be. There are a few documents, but the main one is probably the platform wiki, which you can find below:
- Platform: http://support.ptc.com/cs/help/thingworx_hc/thingworx_6.0_hc/index.jspx?id=thingworx01&action=show
- Edge: http://support.ptc.com/cs/help/thingworx_hc/thingworx_edge/
Note that you will need to set up a login on the support.ptc.com site, which you may or may not have already.