yeah...janeway is the definitive book on immuno...but kuby makes things easier. it's a lot more coherent and definitely much easier to follow. Here's a link on Amazon...i see it's out of print. 🙁, but it's 4.5 stars.
we're using the janeway book now (one of my instructors said it was "simplistic"...then again, he has a phd in the field. i would hope he thinks it's simplistic!). i really like the book, but if you want something that's a bit easier to understand, the BRS for micro/immuno is also very good.
I am currently using the janeway textbook and I have to say that I like it alot. The diagrams have been very helpful. It is probably one of my favorite science textbooks.
The Immune System by Peter Parham is a condensed version of Janeway, with much the exact same figures. They have the same merits except Parham does not go into such depth as Janeway.
janeway one of the most lucid introductory texts i've read to date. parham doesn't include nearly as much information; but if you don't particularly care about that it is a reasonable alternative [a lot of the figures are replicas]