Thanks to Shakespeare's hatchet job of 1593, Richard's reputation as "Dick the Bad" has endured to this day--and has been reinforced in films such as Tower of London (1962).
Shakespear was a great artist - but a Tudor lacky - and very BAD historian.
Anyone interested in a lighter historical read might enjoy the recently republished Daughter of Time by Josephine Tey. A police detective laid up in Hospital with a broken leg reexamines the case against Richard III. Great novel, and not too long.
http://www.amazon.com/Daughter-Time-Josephine-Tey/dp/0684803860