Startup Playbook by Hatch Quarter - A guide to building your startup
CS183B - Startup Class - Stanford class taught by Sam Altman & guest speakers
On Slack by Standuply - The most extensive book on using Slack to the utmost
Classroomies - Watch Stanford CS & Startup lectures together
Frond - A better way to build community online
How to build muscle - An engineer's guide to building muscle.