Lol, what a huge question!
With the comics and the books, there are conflicts and contradictions, sure. Only George Lucas can establish what is canon and what isn't, that makes for some difficulties.
I've never been that interested in the future, so I've read mostly stuff that predates/parallels the original trilogy and/or the latest movie trilogy, but I haven't gotten around to the earliest stuff by Jude Watson yet.
I highly recommend "Rogue Planet" by Greg Bear (TPM-AOTC), and The Hans Solo Trilogy by Ann Crispin (pre-ANH).
I liked "Shadows of the Empire" (TESB-ROTJ), but lots of people didn't like it because it introduces a new evil rival for Luke's power and doesn't focus as much on Vader.
I (and most of the SW fans from what I can tell) did not like "Splinter of the Mind's Eye" (ANH-TESB), but I gave Foster another chance anyway with "The Approaching Storm" (TPM-AOTC) and it was okay.
Brian Daley's Han Solo books are a pass compared with Crispin's. I just couldn't get into them.
I didn't like the "Jedi Academy Trilogy" very much (after ROTJ).
Depends on how you felt about Leia and Han, but "The Courtship of Princess Leia" was worth reading to me, even though I don't think I would have been interested if I hadn't needed to know more about thier romance. It gets sort of. . . unbelievable at times though.
Thus ends my SW novelisation knowledge.
Here's an addy for a timeline site
http://www.galaxyfaraway.com/Books/timeline.htm
I just got "Revenge of the Sith" to read. It's the first book that actually is a movie out of them all that I've ever read, so if you want, I'll come back with my thoughts on it later.
A good guide might be if you've already read an author's sci fi and enjoyed it, to see if they wrote a SW book. That's how I found Rogue Planet, because I already liked Greg Bear. AFAIK, they have to be published and somewhat acclaimed sci fi authors before they can get license to write a SW book.
HTH!