Like Saralonde, I haven't shot a baptism either, but I'd also think that wedding photography tips would be helpful. You might also have a read of some of these links and see if they have some tips. Something I just learned (yeah, I know
) is that apparently the way that it is conducted can vary a lot by denomination, so if you aren't familiar with the ceremony from personal experience, you might want to search for a description of what goes on to figure out what the key moments are.
Anyway, a few links for you
May I ask about Baptismal Photo Coverage? - Digital Photographer Philippines
Digital Photography Tips from the Top Floor :: View topic - Baptism Photos - Compostion Question
Tips for baptism shoot - Photo.net Canon EOS Forum
Christening vs wedding shoot - Photo.net Wedding and social event photography Forum
first Baptism - Photo.net Wedding and social event photography Forum