Tutorials for libGDX and TexturePacker
We currently have these 2 tutorials for libGDX and TexturePacker.
Tutorials for other frameworks are available from the tutorials list.

How to create sprite sheets & animations for libGDX
Free tutorial: Learn how to use sprite sheets & animations with libGDX, speed up startup of your app, reduce download size. Full demo source code included.

LibGDX Beginner Tutorial: Sprite Sheets & Physics with Box2D
This tutorial is for libGDX beginners, explaining how to create sprite sheets, use sprites in your game and add game physics.