Ermm, I haven't really caught up with the conversation, but I don't really think TAC would be a good book to start with. It has too many spoilers. True, it would give you a lot of knowledge as you read through the series, but it would also ruin some of the surprise moments of the series, like when Tobias learns about Elfangor being his father and such. I think it would get people hooked on the books, but isn't the greatest place to start. I think it should be read directly after #23.
The order I read the books was: 1, 10, then complete randomness the rest of the way. I remeber checking #10 out about 5 times before I actually read it.