How to politely reject a professor's request for work that I was recommended for? A very high profile Prof. A recommended me to another high profile Prof. B to do some work for him.  While normally as a graduate I should be very thankful and jump on this, I simply cannot do the work asked due to time and I also believe there would be a more suitable candidate for the work.  Prof A's recommendations hold very high weight in the field I work in (his previous recommendation got me a job as an undergraduate).  I feel that Prof A may have misunderstood my skills (he confused Java programming with Java web programming essentially).  Prof A knows me somewhat well (I work for him currently), so perhaps this is why he recommended me.  

How do I turn down Prof B's request in a polite manner without losing any face to myself or Prof A?  In my response, should I also forward candidates whom I think would be able to do the work (e.g. cc them in the email)?
"While normally as a graduate I should be very thankful and jump on this, I simply cannot do the work asked due to time and I believe there would be a more suitable candidate for the work."

That is more or less exactly what you should say. Express your gratitude to Professor A. If you have a major academic obligation taking up your time, like comprehensive exams or something, mention that. Do NOT CC the candidates you have in mind, but do mention to Professor B that you can recommend someone else who you think would be a good fit.