what is the best way to take photos for use with lightroom 4, JPEG or RAW?
Raw, Yossha. The point of Lightroom is that it's primarily an excellent Raw converter, so you'll waste much of its ability and value if you only throw jpegs at it.
I agree that Lightroom shines as a RAW processor and editor ...
But also Lightroom does a great job cataloging and editing your previously captured JPGs
Oh yeah, true enough, but I didn't get the sense that the original question was about Lr's DAM capabilitles - and Lr wouldn't be my first choice for a jpeg editor.