My advice was no. It's not a rigorous presentation of the evidence for or against, and neither (to be fair) is it supposed to be: it's a thriller, and should be judged on that basis. I think reading historical books about the development of Christianity would be a better approach. Of course history and polemic are hard to separate, so I would think it best to read books from both sides of the debate.
But the obvious question - which books? Can anybody recommend me some non-fiction books that deal with the same kind of issues that the Da Vinci Code does? I'm thinking about the position of women in the early church, the suppression of the additional gospels at the council of Nicea, the gnostic movement, plus of course orthodox histories of the period which take a less confrontational line. I'm going to think about it a bit, and post any ideas that come to me as comments, but other recommendations would be welcome.