The Men's Bible Study Series (now free downloads!) developed by the Presbyterian Church, USA is an excellent series of 19 - 7 week studies on books of the Bible and their particular message to issues facing men.
The Fellowship of Carpenters is one of the best small group studies for men available. "Rules of the Trade" is an excellent foundational study for introducing men to the transformational power of God through small group ministries.

What Really Matters: Conversation Starters for Men is the new resource developed by Mennonite Men. What a wonderful tool this is for helping men explore key issues they face today. A key element of this resource is its focus on men's accountability one to another, a vital ingredient to men's spiritual formation.

Master Builders Bible for Men is a terrific resource produced by Lutheran Men In Mission. In one resource you have an NIV Bible, 20,000 study questions and 6 courses of study for men!
T-Quest for Men is the newest resource from the United Methodist Men. It is a gripping ministry designed for groups of 4 or 6 men that brings about transformation through the study of and accountability toward living the abundant life .
The Men's Ministry Action Plan, distributed by the United Church of Christ Men's Ministries, is a three week discernment process for prayerfully developing an action plan for a congregation's ministry to men.