My all-time favorite IBM mainframe assembler text is Peter Abel’s Programming Assembler Language: IBM 370 series architecture and assembly language.
I first taught assembler using a an early version of this book in 1980. Our department faithfully used this book for twenty plus years, even after it went out of print. (Perhaps a record for a continuously used college text.) It has good descriptions, few mistakes and lots of good examples. You can still buy used copies on the Web for a few dollars (a bargain), but if you decide to buy one, be sure you get the mainframe version – Professor Abel also wrote a PC assembler book.
Dr. Edward Bosworth, a colleague in my department, wrote his own assembler textbook, partly based on Abel’s material. It’s well written, very complete, and includes some terrific historical material. An attractive feature of his book is that it’s available free on the web: http://www.edwardbosworth.com/My3121Textbook/MyText3121_AFrontMatter_V03.htm
Give it a try, it’s a good read.
And, in case you haven’t already stumbled over it, you can also find my own material here: http://csc.columbusstate.edu/woolbright/WOOLBRIG.htm