There is a family of free and open-source graphic design softwares that are popular with a large community of users that love to help each other out. Gimp is a photo manipulation art design software for raster imagery, which is visuals that are like photos. Inkscape is a drawing and design software using vector tools, which are more graphical. Scribus is a page layout and publishing design software.
Below you'll find a few short introductory videos and to the right are links to TJ FREE's courses on these three open source softwares. These courses are fantastic for beginners and will get you familiar in no time.
But there's more to design than simply learning the tools, so we included a few little videos on design theory as well.