Check out these from Tim Keller: Preaching the Gospel, Persuasion, Gospel Preaching and his Preaching the Gospel in a Postmodern World course on iTunes U.
Check out John Piper on the Pastor as a Prophet free course through Re:Train. Solid.
Also, I consider this a MUST LISTEN from Andy Stanley, even though it’s not free, and I don’t fully agree with him.
Listen to “Preaching Across 3 Streams” from Jonathan MacIntosh.
Download session 1 of Acts 29 Quarterly here (James MacDonald).
Listen to Darrin Patrick talk about Missional Preaching.
Find out how to avoid the “stillborn sermon” from Andrew Vander Maas.
Check out “Preaching and Preparing a Gospel Centered Message” by Dick Kaufman.
Read this preaching evaluation form from Tim Keller.