Gimp is a pretty popular free paint tool. This artist creates brushes for Gimp and Photoshop. There are dragon, planets, butterflies, plants etc... It's very very useful for creating backgrounds and sprites. All brushes are free and no-credit (read the ToS though).

These tutorials are all for Game Maker. The tutorials should help you start building games with the software and learn how the scripting works. They have small script examples.

Sakari-Infinity is a website that allows you to download free music, as long as you don't alter or sell it etc. It's a great site if your looking for background music. All Audio Files provided by Sakari Infinity are licensed under a Creative Commons.