I haven't read the books myself, but I've just had a look at the descriptions for the two books on Amazon and they appear to cover different subjects:
- What it means to behave as a true software craftsman
- How to deal with conflict, tight schedules, and unreasonable managers
- How to get into the flow of coding, and get past writer’s block
- How to handle unrelenting pressure and avoid burnout
- How to combine enduring attitudes with new development paradigms
- How to manage your time, and avoid blind alleys, marshes, bogs, and swamps
- How to foster environments where programmers and teams can thrive
- When to say “No”–and how to say it
- When to say “Yes”–and what yes really means
- How to tell the difference between good and bad code
- How to write good code and how to transform bad code into good code
- How to create good names, good functions, good objects, and good classes
- How to format code for maximum readability
- How to implement complete error handling without obscuring code logic
- How to unit test and practice test-driven development
I think Clean Code is about a developer and his code, while The Clean Coder is more about the general aspects and external factors you have to deal with as a developer.
With this information it is up to you to decide whether or not you should read Clean Code as well, but I think it's safe to say it will definitely teach you something. It's been on my list of books I want to read for a long time.