Hey Oinkness!
I'd be glad to answer any questions that you have about my "methods and training". However, every piece is different and I do not like to limit myself to specific programs or techniques. My background is in the Video Post Production industry. I have been working with 3D animation, video compositing and graphic design since 1993. I also do a lot of work with film restoration and DVD menu design.
You asked about layers and transparency, etc... Yes, these pictures are made up of MANY, MANY layers (probably 50-60 layers each) combined together to create the final image.
Using layers is extremely useful for creating complex images. It allows you to modify and change parts of the image without changing other areas. I would suggest taking a Photoshop class at a community college to learn the basics. If you are enrolled as a student, you can get HUGE savings on "academic versions" of Photoshop and other professional software packages.
I usually use Photoshop or Adobe Aftereffects for my final composite, though I try to bring in elements and different layers from other programs to create the desired look, texture and mood. This can include anything from digital and traditional photography to 3D modeled and rendered computer generated images to high resolution scans of traditional art (paintings, drawings, carvings, sculptures, etc.) as well as frames from video footage.
If you, or anyone else, have any specific questions, let me know and I'll do my best to answer them for you.
Dan