Offline to the forums over the weekend, so I'm late getting back in here.
datalink7, you might try Job: A Comedy of Justice, or better yet, Friday. Then go back and find as many of Heinlein's old "juveniles" as you can (those were short novels written specifically for the youth/school library trade, published originally by Simon & Schuster). Podkayne of Mars is great, as is Red Planet (and try to get copies of the old and the new versions - the differences related to what was considered to be "acceptable" behavior and actions for girls vs. boys then and now are rather telling...).
IIRC, Grumbles from the Grave gives a complete list of his published works, as well as offering information about old vs. new versions of several of them. (Podkayne, Red Planet, The Puppet Masters, and Stranger are the ones that show significant differences.)
And I was asked a question offline about the McCaffery Pern series, which answer I will repeat (in part) here. If you are not familiar with Pern, you need to start with The Dragonriders of Pern, a trilogy that includes Dragonflight, Dragonquest, and The White Dragon. If you can also lay hands on the Harper Hall trilogy as well (Dragonsong, Dragonsinger, Dragondrums), so much the better. (It's out of print, but available through the usual used book sources.)
Those six books define the Pern universe - all of the rest are pre-history or add-ons, and do make assumptions about your basic knowledge of all that is Pern.
Happy reading!
Edit: I own at least one copy of everything sci-fi RAH has written that was published in book form over the years. (That includes just about all of it; there may be one or two short stories that never made it to book format, but my library pretty well matches the list from Grumbles.) I'm happy.
Lady Niniane