for diving the best book to have is your diving manual.
also if you are looking for megazine out there...theres a lot..all are good...it is only up to your preference.
Kino have a good selection of books and megazines on diving.
as for freediving..sad to say that there are no publications out there.
But there is a freediving manual by ex world champion Umberto Pellizari called Manual of Freediving which you can get in Kinokuniya in the sports section. price is around RM 160. This is a very good book and i am using it myself.
also i got a few books on free diving in my library and you can borrow them if you want.