That link u posted u were followin is more then just root, the guys got you rooting which is only the gingerbreak part at the top, the he's got ya installing setcpu to overclock or undervolt, I'd say currently don't play with either of them, and finally he's got you installing a custom recovery, the easiest place I see a mistake may have come in is it seems he has a zip to download with the clockworkmod image inside, if this is the case you'll need to unpack in, not move the whole zip, also names are important, must be named recovery.img no spaces or anything.
Further down he starts going into more stuff you can install but most are probly optional,, also while inside the mobile folder when its in download mode you only wanna touch the recovery.img, if ther things like start up sounds of shujt down sounds are removed the phone wont be able to do either