Speaking and Listening

Advice on Giving Colloquium Talks, from John E. McCarthy
Advice on Giving Talks, from Jordan Ellenberg
Be considerate of your Audience, by Terry Tao
Talks are not the same as papers, by Terry Tao
Advice on getting the most out of talks, from Ravi Vakil
The MAA has a compilation of advice on giving a math talk.
The Mathematics Students Resource has more advice on giving math talks.
The Mathematics Students Resource has worksheets for preparing talks on The Big Picture and The Finer Points, as well as a Talk Checklist Form