Regarding Anne McCaffrey: mostly going to be female protagonists, will your son be ok with that? The Harper Hall trilogy (Dragonsong, Dragonsinger, Dragondrums) fine for 10 yr old -- my kid read them age 10.
But be careful with McCaffrey's other books -- they'll tend to have a bit of romance-novel-light-sex, and you mention you're trying to stay away from sex yet. For instance, Dragonflight, her very first "Dragonriders of Pern" book (which the Harper Hall trilogy fits in sort of sideways with), while I enjoyed it myself when young, has a almost-rape-that-turns-into-love-relationship. It's not at all graphic, at least as I recall -- but maybe a dubious message for a 10 yr old.
