This is a great introduction to ARM processors at the assembler level. It covers some pretty fundamental stuff, but also extends to some more advanced topics. It has been written with real applications in mind, with snippets of really useful implementation tips throughout the book.
Being able to access a demo version of the Keil tools allows you to get going on the examples and try things out yourself straight away (Shame there's not a linux version though).
I'd definitely recommend this to beginners and moderate assembler programmers. Although even advanced programmers would probably gain from reading a few of the sections.
Only downside is the price, which is a bit steep.