Here are some Books you may be interested in

Digital Manga

Digital Manga Workshop(if you live near a shop called the works get it from them retail price is normally £17.96 I got a copy from them for £2.99 i don't know if that offer is still on mind you)

The Monster Book of Manga

The Monster Book of Manga Boys

The Monster Book of Manga Girls

Manga Mania

Digital Manga All about Fighting (I got this for 99p at the works normal price is probably around 8 Pounds.)

The Complete Guide to drawing Manga

Shojo Manga

Shonen Manga

Stan Lees How to make Comics

 

There are a lot of books I haven't mentioned but these are all good to and here are some mags you might like to try

Imaginefx

Advanced Photoshop

and

Photoshop user.

 

Hope This Helps

 

Karl