how to embed ruby code

I am very much a novice learning ruby code right now. I already know
how to write the code and open it in a command prompt. My question is
how do I embed it into an html document? how do I use rails? Im not
sure where to go from here. I've been reading tutorials but havent
found any clear direction. Can someone please steer me in the right

I'd take a look at

Fred by Michael Hartl is a wonderful resource.