This is more history than fiction, but......I love medieval historical novels, especially British, but I have a terrible time following the players in the War of the Roses; mostly the Yorks and Lancasters, and who did what to who, when, and which king was who, etc.

Which advisor was really acting as king, to which weak ruler.....that kind of thing.

Is there a good, easy factual summary anywhere, OR (and I know these are two different things) is there a book that really lays it out in a form that's easy to follow?

I've poked around with google a bit, but it seems the summaries I've seen are more complicated! Or they just deal with a little slice of it...or maybe I need a grpahic? (I've seen the geneological tables, that's not much help)

Boy, that's a tough one and I don't think there's a simple answer for you. IMHO Penman's Sunne in Splendour is still the gold standard, but then it's no light, easy read either. The family relationships are so complex and a lot of the disputes over ruling houses goes back to Edward III and Richard II (I think that's them). Carol Wensby-Scott's Alnwick trilogy is awesome, but I don't recommend it for newbies. 

If you're seeking non-fiction, I highly recommend Paul Murray Kendall's Richard III. You'll get a thorough education in the players, how it all started, and how it ends. Penman's book is the fictional version, IMO. Either should work and be enjoyable.

I second The Sunne in Splendour by Sharon Kay Penman.  I read it in February; well, during ALL of February, to be precise. It's a monster. But I loved it!  I was able to keep the players straight, and understand the complexities thanks to SKP's skill.  

I picked up a novel about the little princes yesterday and found that, because of Sunne, I knew the characters mentioned, and I'm probably getting more out of this book than a reader who has not read Sunne!  So SKP's layout of the time, characters and politics has stayed with me.  It's nice, because most days I wonder if dementia isn't lurking over my shoulder! *eye roll*

One of the difficulties in reading or studying British history is the tendency to repeat names, and you're left asking, WHICH Edward, Richard, Henry was that?  For example - from the War of the Roses era - King Edward IV had a younger brother named Richard (later King Richard III).  Edward IV also had two sons - named Edward and Richard (later the Princes in the Tower).  Richard III had a son (who predeceased him) named Edward.  Confused yet?  The father of Edward IV and Richard III was named - wait for it - Richard.