This will tell you most everything you need to know about The Vision. There are no spoilers but some speculation that I hadn't heard before I saw the movie (it was done before the movie was released). Since I haven't read current comics since 2002 I have no idea about any nonsense past Master Pandamonium, which was bad enough (not to mention two Torches).
They did leave out one small detail I would have put in there- mentioning the original, otherworldly Vision, Aarkus. He's rather cool and deserves to be mentioned. I never knew there was an original until years later.