If I may blow some horn, I explain a bunch of terms for exactly this purpose at www.GreatHomeTheater.com, my website - it's written for those who don't know these things.
Something to keep in mind is that the HDMI interface supports HDCP which is copy protection. Without it you might just find yourself being DOWN-RESOLUTIONED by the evil forces of copy protection into a less than optimum picture. So that's a key consideration.