The first book, Dragons of Autumn Twilight, introduces us quickly to the adventuring party, and jarringly throws them into a quest.  The authors don't wish to stretch the minds of their readers overly much, so they give the characters names that make it easy, like the dwarf Flint Fireforge, and the party's leader, Tanis Halfelven.  Tasselhoff Burrfoot, a member of the halfling/hobbit replacement race they call kender, rounds out the three who we first meet.  They are obviously reuniting after taking some agreed-upon separate quests, and have returned home.  Within a few minutes they rejoin the knight Sturm Brightblade, who arrives with the barbarians Goldmoon and Riverwind.  Rounding out the party are the brothers who stand out because their names don't completely suck, but nonetheless embrace D&D stereotypes so strong that the Order of the Stick couldn't've done a better job mocking them:  the fighter Caramon (18/00 strength, 6 intelligence) and the magic-user (yes, they actually use the term "magic-user") Raistlin (3 constitution, 18 intelligence), who are twins despite their differences (oooh, there's a concept!).  Within a few minutes a brief skirmish forces our characters to run for their lives and find themselves on a desperate quest to find a holy artifact which is the only hope to repel armies that have appeared out of nowhere for no clear reason, forcing them to cross half a continent and kill two dragons (or was it three?) while narrowly avoiding death themselves countless times . . . all in the span of about three days.  They are continually faced with things no living man has ever laid eyes upon and lived (forests of dead spirits, secret city of the elves), and miraculously survive insurmountable odds time and again.  
If Tolkien thought it useful to have a guide or wisdom-keeper like Gandalf to aid his characters, Weis and Hickman drizzle them liberally upon this first volume, including encounters with a talking unicorn, a long-lost goddess, and a wizard who is seemingly incompetent, and so is likely to be vastly powerful and just along for the ride.  These various beings complement the remainder of the two-dimensional characters nicely, and join the plot with no more smoothness than any other plot device.  The wizard Fizban, for instance, is encountered standing on the side of the road, and joins the party because, well, it must have been obvious that this is what the DM wanted at the time, and we all know things go easier if we let the DM tell the story.
One maddening aspect of this book is the authors' attempt to pummel the reader into accepting that all of the characters are equally important.  Instead using traditional techniques (for instance, giving each of the characters some reason to exist beyond the fact that it was rolled up for a game), they use third-person perspective much like the Chinese used water on their enemies in ancient times.  During the course of the book, most notably during fight sequences, the perspective flits about from character to character like a faerie with diarrhea searching for a daisy in a rosebush.  No warning is given, such as a transition or paragraph break, to signal these shifts.  By the end of one of these scenes the reader is left dizzy and very nearly nauseous.
Fights themselves come in two stripes:  the ones the authors wrote down during their D&D game and the ones they didn't.  It's easy to tell the difference; if it went on for three pages they wrote it down, if it takes place in a paragraph's time, they didn't bother.  They describe, for instance, the condition of one character after being fatally breathed upon by an acid-spewing black dragon with such rapt detail you can clearly see the grotesque results of the attack.  On the other hand, they continually mention, and then gloss over, exactly how the mage Raistlin and his brother Caramon fight very well together - we only know that they prefer to do nothing but.  My guess, which is supported by the notes at the end of the book, is that neither of these characters were played by the authors, so careful records just weren't kept.