The FIX Guide was developed for professionals in the fixed income market to understand how to implement a system utilizing the FIX protocol. Written for business and product managers, the Guide is a high level view of the resources and skills necessary to exploit the preeminent global standard for the electronic trading of fixed income. Highlights include choosing FIX engines, network choices, testing, the rules of engagement and the FIX process for fixed income. As more trading partners and platforms develop FIX messaging capabilities, firms are looking for an understanding of the most efficient way to implement FIX. The second edition of the FIX Guide draws on the expertise and resources of over 30 industry participants.
This is the most useless technical book that I have bought and read. The problem for this is it's not widely available so you cannot sample it before buying it.
If you are a developer and require information on Fix, it might be easier to just read the documentation of QuickFix and technical documentation from exchange for their Fix interface!!!