I'm in the process of learning a new program for work and have been able to send the pdf manual to my kindle. So far, so good. Pages look right, no problems with text. I haven't gone through the whole thing (either online or on the kindle) so I don't know whether there are graphics in the file.
I will say that I was Very pleasantly surprised at how nice it looks on the kindle and I love that I can carry it around with me and learn while I'm on line at the store and so on.
What I Really loved though was the publisher specifically spelling out that the book could be printed (pdf) or copied electronically for learning.
I really didn't want to print it all out for carrying around, so being allowed to read it on the kindle is quite a cool thing.
that said, I think if the majority of my reading were pdf based, I'd try to spring for an Iliad, probably used as they're a bit too pricey yet for me (I do love the idea of them though)