Global missions
Identifying most urgent needs - Stratus
Unreached people groups - Urgent
Unreached people groups - Joshua Project
Praying for the nations - Prayercast
Praying for the nations - Operation World
Prayer requests for persecuted Christians - Voice of the Martyrs
Supporting persecuted Christians - Open Doors
Partnering with persecuted Christians - Voice of the Martyrs

Online study resources
Online Commentaries - Gospel Coalition
Online Bible and study resources - NET Bible
Online Bibles and study tools - Bible Gateway
Online Commentaries and Articles - Precept Austin 
Language Resources - Blue Letter Bible
Language and Reference Resources - Bible Hub
Language and Reference Resources - Study Light
Bible references, visualization and geocoding - OpenBible


Apologetics and Discipleship Resources
Pastoral questions - Desiring God
Common Questions - GotQuestions
Core Doctrines - New City Catechism

Sermons and studies
Audio sermons - Gospel Coalition
Audio sermons - SermonAudio.com
Audio messages - Desiring God
Audio messages - Truth for Life
Audio messages - Gospel in Life

Classes
Online classes for all levels - Biblical Training Institute
Free online learning - Gospel Coalition
Free online seminary courses - Southeastern Baptist Theological Seminary
Free online seminary courses - Dallas Theological Seminary

Video resources
Video lessons and studies - RightNow Media
Video introductions to books and themes of the Bible - BibleProject
Extended Biblical study - Secret Church

Podcasts
Companion to M'Cheyne reading plan - Into the Word
Pray the Word - Radical
Sermons - Timothy Keller
Bible studies and theology - BibleProject
Discussions and lessons on Bible study and growth - Gospel Coalition
Persecuted Church - Voice of the Martyrs