We currently have these 3 tutorials for libGDX and TexturePacker.Tutorials for other frameworks are available from the tutorials list.
This tutorial is for libGDX beginners, explaining how to create sprite sheets, use sprites in your game and add game physics.
This tutorial explains the most used sprite sheet types and how you can easily create a sprite sheet from a single of images. Links to free software included.
Tutorial: Create sprite sheets for your normal mapped sprites.