I never read it C to C per se, but on multiple occasions I've read and re-read so many parts (all of them AFAICR) as to have in effect read the entire book at least once.
had to read it multiple times ... I keep forgetting entire sections and then have to reread them.
and plus when I'm on the thinking-throne I like to start from the ... *wolf thinks for a moment* ... yeah, you guys probably don't want to know that much about my reading habits!
Everything except the spells multiple times. I read spells up through the D's and then just started skipping to spells I was interested in or checking them out as they became relevant to play.
I read it cover to cover within a day of having purchased it when it first came out, and I keep going back and rereading whatever particular part interests me at the time. What can I say, I love rule books, they make me feel all warm and fuzzy.
I've read all the classes, and I have read all of chapters 1-7, but I think I skipped some of the information from the Combat chapter. And I only read spells when I need the information. I oftentimes look up specific spells before a game, to be informed. I read the Combat chapter before a game as well.