Lesson number2; You can use a Custom Recovery to install a Custom Rom or as some ppl call it "Flashing" a rom which usually comes in a zip file. Remember in the beginning you "rooted" your phone? This gives you full control of your Rom, kinda like an Adminstrator. Well if your rooted you then can install a custom recovery, right? Here's the part nobody tells the noobs. When you flash a custom rom whom ever builds the rom would generally root it for you first by installing Superuser to the system. Hence the words "rooted rom" for instance Droidsmith Force Beta is a rooted rom. There may be in some cases when somebody actually puts out a rom that is not rooted, so then you would have to go thru the rooting process again but this is rare.
Warning;Rooting and installing a Custom Recovery voids warranty!