Well, I'm not a very good programmer, but a few years ago I looked into this free ebook on PC asm, I know it isn't ARM asm, but it could be a useful start. I just happened upon this thread so I don't happen to have any useful links to free books for ARM assembly, but I'd imagine a lot of the same principles still apply and can be utilized.

Here is the link to the aforementioned book:
http://www.drpaulcarter.com/pcasm/

Hope it helps and best of luck!