You may want to see these general resources about alternative dispute resolution:
Alternative dispute resolution, or ADR, is a "procedure for settling a dispute by means other than litigation" (Black's Law Dictionary). Common types of ADR include mediation and arbitration, both of which require negotiation skills on the part of the attorney. Mediation and arbitration involve a neutral third party who helps the disputing parties reach a resolution. A mediator's recommendation is not binding, while an arbitrator, as a rule, makes a binding decision.
This subpages of the guide covers resources on negotiation, arbitration, and mediation.