Assuming you're already rooted and have CWM installed, those are the correct steps imo to install a new ROM. Remember you have to download the appropriate GApps (The Google applications, because the can't be bundled with ROM's, for the specific Android version you are installing) and place this on the root of the SD card. After flashing the ROM in CWM, flash the GApps with the same method before rebooting.
Regarding the root procedure, there are different method. I downloaded a root version of CWM and flashed it to the phone with Odin. It rooted the phone automatically and installed CWM. From there I proceeded with the flashing of the ROM. I can't find the guide now, but I'm not an expert at rooting unfortunately. The other guys would be able to assist you further.
You could look at the guide from Cyonogen Mod. I trust them.
ffs, can't edit or posts links. Here is the link for the Cyonogen Mod installation guide.
http://wiki.cyanogenmod.org/w/Install_CM_for_i9100