***actually admits he's never read Heinlein***
Where should I start?
Hmmm... that's a harder question than you'd think. The best time to start Heinlein is when you're a 12 year old boy. Or a reasonable approximation thereof. 12 year old girls are ok too. It works best when the world is shiny and new as your latest Scouting badge.
That said, his books are marvelous. My personal favorite is "The Rolling Stones". You might try one of his short story collections, probably "The Man Who Sold The Moon" or "The Green Hills of Earth". "The Moon is a Harsh Mistress" is a pretty libertarian piece of SF.... not written for kids... which you either love or hate. "The Door Into Summer" and "Double Star" are the other two novels that sort of sit on the cusp between his juvenile fiction and his weird stuff, IMO, and so make an easy read.
But, to start, you might want to pick up The Past Through Tomorrow, a collection of short stories and novellas that pretty much defines his Future History. From there, you want to read Starship Troopers, and The Moon Is A Harsh Mistress, and the "Boy's Life" books, of course.
Jen, what do you suggest?