Many critics put a lot of faith in the anti-Mormon spin on the Book of Abraham. But it’s blind faith, or at least “squinting” faith, that can’t withstand much observation. Look at The Book of Abraham Project, a rich source of well documented information on the Book of Abraham. To deal with the common objections raised by critics, look at their page on Criticisms of Joseph Smith and the Book of Abraham, which refutes most of the attacks made on the Book of Abraham.
I also have my own pages on the topic: “Ancient Evidences for the Book of Abraham: Other Records Confirm its Story,” which challenges the critics to explain how so much of the material in the Book of Abraham is confirmed by ancient documents that Joseph could not have known about. As for the specific attacks of the critics, see my page, The Truth About the Book of Abraham, Part 1 and The Book of Abraham, Part 2 – Evidence that Joseph Smith was a Prophet of God.
The Book of Abraham is one area where I really feel that Mormons can turn the tables on our critics and start asking some tough questions of our own.