Comment The Harvard Negotiation Project (Score 1) 361
Besides the "god gave you one mouth, but two ears" most of the communication you will need is around negotiation. Here the Harvard Center for Negotiation published an excellent series of books: Getting to Yes, Getting past No, Difficult conversations, Lateral leadership and the Power of a positive NO. I wrote a little about it: http://www.wissel.net/stw/wisselblog.nsf/d6plinks/SHWL-6LR37S
You also might want to check out Toastmasters who hone speaking skills or "The contrary public speaker". While they are not strictly about communication, they are about making your point understandable (litmus test: explain to a Rotary Club what a Social Graph is - they live it, but the don't use that lingo).
Hope that helps