Intro: Minecraft Tutorial - TNT!!!
Here is another Minecraft tutorial all about tnt.
Step 1: Single Cannon (automated)
Here is how to make a cannon where you load, then press one button only.
Step 2: Double Cannon
How to make a cannon that shoots 2 ways!!
Step 3: Wiring a House to Explode!!!
note: i take no credit for you blowing up your friends house