Video Editing And Special Effects

[airman]

for a mid term project, i have to make a video for world history. it's supposed to be about a roman/greek type myth, you know what i mean. and i want to have a totally kickass video...and i was wondering how easy it is to do blue/green screens. i know some people at my school HAVE used them in their videos before, but they've already graduated

 

i know it's simple to set up the actual greenscreen, all you have to do is have equal lighting on the background. easy enough. but how would i go about superimposing someone's image over a video? (i plan on pausing the still action, and having a narrator come infront of the screen and talk about it) and what software would i need?

 

i've done plenty of actual video editing, so i know how to do that, as i helped my older brother with it last year, just no special effects.