I've yet to see a decent HTC rooting video so I don't know what they told you.
Before doing anything else, make a nandroid backup of your stock setup, right away. Always nandroid backup before making any root changes.
Never flash anything without checking the md5 checksum first.
If you bootloop after installing a rom you'll need to separately flash the boot.img.
If you need help with any of that, please ask.
Don't become the excited guy who takes shortcuts on nandroids or md5 checking, it's the road to ruin.
PS - trial and error on a recovery image and you didn't turn your phone into a paperweight. Thank your lucky stars, I don't think you realize what bullet your just dodged.