Arthur Blessitt: Three evangelism books online free.
Bunyan Archive: Complete works of John Bunyan online.
Concord Road Church of Christ: Evangelism Handbook: Surveys methodology, doctrine, apologetics, and Christian living (HTML, DOC, PDF).
God 101: The Abundant Life: A simple course showing God's key to the abundant life that Jesus promises every person. Several formats are available.
Mercy Street Ministries: Street University: By Richard C. Hobbs, training in street evangelism (PDF).
Power Evangelism: Notes from John Wimber's landmark book.
Street Preacher's Manual: Read Gerald Sutek's guide online free.
Watchword Revivals: Read online classic revivalist authors such as Finney, Nee, Tozer, Spurgeon, and Booth.