The Holy Bible is the primary resource in sermon preparation and preaching. secondary resources such as commentaries and websites are used to enhance, not replace, personal interaction with Scripture.
Any sermon is a combined effort of using multiple sources of research and collected life material. The sermons prepared are the result of gleaning, reading, and leading of the Holy Spirit. Citation is important in presentation of publications but blocks the flow of connection in preaching. Sometimes citation is given a backseat to communication.
Authors and Materials I appreciate, read, and utilize:
The Bible (NIV and MSG are my favored blend),
AUTHORS: Vance Havnor, Ron Dunn, WA Criswell, Charles Swindoll, Ogilve, Yancy, Tom Rainer, Arthur Pink, Gordon McDonald, Max Lucado, Doug Fields, James Dobson, Geiger, Groeschel, Ed Young (older and younger), Stanley (older and younger), Bobby Welch, Billy Graham, Dave Ramsey, John Maxwell. I read in excess of 50 books a year.
SOFTWARE: Logos, WORDsearch, Accordance, BibleGLO, I-tunes for Podcasts, Kindle for Ebooks, iMovie.
Online resources I find most useful: Google, Sermonspice, Encouragingmusic.com, rimshot graphics, Sugarsync.com, dropbox.com, Evernote.com, Day One Journal App, Discipleship Journal Collection.
Commentaries/ Bible Resources: Preachers commentary, Broadman, Pulpit Commentary, Harpers, Henry, Weust, Strongs.