hboot=bootloader. its the white screen with colored lettering that lists your bootloader,radio,etc. info. since youre new to rooting and roming,all you really need to know about it at this point is that its a way to access clockwork recovery,wich is what you will use to make backup,do wipes,and flash roms,as described above.
quickboot is a market app that you can use to boot into clockwork recovery,its nothing more than an easier way to get to it.
again,clockwork is what we are refering to as "recovery",which is where the menus are to wipe,backup,and flash.
hope that helps

feel free to ask questions,as its definately better to learn before,rather than after,when your phone is in an unusable state