What movies?
The Truce of Bakura occurs IMMEDIATELY after ROTJ. As for the series, do not miss out on The Thrawn Trilogy, as that is the best. Other good series include The Corellian Trilogy, the Han Solo Trilogy (but read this only after you've read other series' first), the X-Wing series (good for the starfighter, military side of Star Wars, not much Jedi action here), and the Jedi Academy Trilogy (kinda for young adults, though). Another good book is Shadows of the Empire which takes place between the E5 and E6 and does a good job linking those two movies. I would also check out the Tales of the Bounty Hunters, Tales from Mos Eisley Cantina, and Tales from Jabba's Palace. Those are collections of interlinking short stories that deal directly with the bit parts from the original three movies.
Oh, and also the ginormous New Jedi Order books after that.