Check out the following computer graphics resources and tutorials:
Intro to Photoshop Mixer Brush:
http://www.photoshoptutorialsandtips.com/photoshop-tutorials/the-mixer-brush-tool-in-photoshop/
Creating Pixel Art tutorial:
https://www.google.com/search?q=how+to+do+pixel+art+in+illustrator&rlz=1C1GGRV_enUS782US782&oq=how+to+do+pixel+art+in+il&aqs=chrome.0.0j69i57j0l2.5407j0j7&sourceid=chrome&ie=UTF-8&safe=active&ssui=on#kpvalbx=1
Digital painting tutorial using layers in PS:
http://www.floobynooby.com/ICG/artvalues.html
Create Portraits using Typography in PS:
abduzeedo.com/super-easy-typographic-portrait-photoshop
Create Type portraits in Illustrator:
www.instructables.com/id/How-to-create-a-Typographic-Portrait-in-Illustrato/
To create a flower design for a coloring page in Illustrator:
http://wegraphics.net/blog/tutorials/how-to-create-a-stress-relief-coloring-book-page-in-adobe-illustrator/
To create a realistic sun in Photoshop
_http://design.tutsplus.com/tutorials/how-to-create-pixel-art-icons-in-adobe-illustrator--cms-22941
to create pixel graphics and icons in Illustrator
http://www.digitalartsonline.co.uk/tutorials/adobe-illustrator/create-low-poly-portrait-photoshop-illustrator
Site to create low-poly portraits
http://www.cgsociety.org/ Site dedicated to digital artists specializing in 3D graphics and animation.
http://www.webdesign.org/photoshop/imageready-animation/how-to-make-an-animated-banner-in-photoshop-cs3-video-tutorial.17668.html
Shows you how to create an animated Web Banner in Photoshop!
http://sixrevisions.com/graphics-design/40-useful-adobe-illustrator-3d-tutorials-and-techniques/
This site has many Illustrator tutorials that help you create amazing 3D images!
http://www.digitalartsonline.co.uk/tutorials/?featureid=3302703#1 This site shows you how to create cool cosmic art using existing photos and liquify filters in Photoshop
http://www.photoshoplady.com/tutorial/pop-art/292 Tutorial to create a Roy Lichtenstein style Pop Art portrait in Photoshop
http://www.vineyardesigns.com/tutorials/photoshop/index.shtml Shows you how to use Photoshop to create a website layout.
http://designertoday.com/Tutorials/Photoshop/4387/Selecting.Hair.Adobe.Photoshop.CS3.Tutorial.aspx To select hair that is complicated.
http://www.psdeluxe.com/articles/tutorials-showcase/best-photoshop-tutorials-stunning-photo-effects/ This site has 40 tutorials that show you how to create stunning photo effects. A lot use images that cost money, but you might get some ideas and use other photos or your own images.
Intro to Photoshop Mixer Brush:
http://www.photoshoptutorialsandtips.com/photoshop-tutorials/the-mixer-brush-tool-in-photoshop/
Creating Pixel Art tutorial:
https://www.google.com/search?q=how+to+do+pixel+art+in+illustrator&rlz=1C1GGRV_enUS782US782&oq=how+to+do+pixel+art+in+il&aqs=chrome.0.0j69i57j0l2.5407j0j7&sourceid=chrome&ie=UTF-8&safe=active&ssui=on#kpvalbx=1
Digital painting tutorial using layers in PS:
http://www.floobynooby.com/ICG/artvalues.html
Create Portraits using Typography in PS:
abduzeedo.com/super-easy-typographic-portrait-photoshop
Create Type portraits in Illustrator:
www.instructables.com/id/How-to-create-a-Typographic-Portrait-in-Illustrato/
To create a flower design for a coloring page in Illustrator:
http://wegraphics.net/blog/tutorials/how-to-create-a-stress-relief-coloring-book-page-in-adobe-illustrator/
To create a realistic sun in Photoshop
_http://design.tutsplus.com/tutorials/how-to-create-pixel-art-icons-in-adobe-illustrator--cms-22941
to create pixel graphics and icons in Illustrator
http://www.digitalartsonline.co.uk/tutorials/adobe-illustrator/create-low-poly-portrait-photoshop-illustrator
Site to create low-poly portraits
http://www.cgsociety.org/ Site dedicated to digital artists specializing in 3D graphics and animation.
http://www.webdesign.org/photoshop/imageready-animation/how-to-make-an-animated-banner-in-photoshop-cs3-video-tutorial.17668.html
Shows you how to create an animated Web Banner in Photoshop!
http://sixrevisions.com/graphics-design/40-useful-adobe-illustrator-3d-tutorials-and-techniques/
This site has many Illustrator tutorials that help you create amazing 3D images!
http://www.digitalartsonline.co.uk/tutorials/?featureid=3302703#1 This site shows you how to create cool cosmic art using existing photos and liquify filters in Photoshop
http://www.photoshoplady.com/tutorial/pop-art/292 Tutorial to create a Roy Lichtenstein style Pop Art portrait in Photoshop
http://www.vineyardesigns.com/tutorials/photoshop/index.shtml Shows you how to use Photoshop to create a website layout.
http://designertoday.com/Tutorials/Photoshop/4387/Selecting.Hair.Adobe.Photoshop.CS3.Tutorial.aspx To select hair that is complicated.
http://www.psdeluxe.com/articles/tutorials-showcase/best-photoshop-tutorials-stunning-photo-effects/ This site has 40 tutorials that show you how to create stunning photo effects. A lot use images that cost money, but you might get some ideas and use other photos or your own images.