I'm not really clued up on the beggining books, but I swear by the O'Reilly books,
I currently have "MySQL & mSQL" costs about £25, well worth if for a starter and reference.
I also have Microsft SQL Server (Microsft Press), believe me stay well clear from this one.
I also have the PHP books by O'Reilly.
And I can't remember who's it's by and my mates borrowed it but it's called "PHP Cook Book".
Just search Amazon and read the customer reviews, they will tell you if it caters for you.
Hope this helps