Welcome to the club! "Understanding Exposure" is a great book I read when I started out, covered all the bases in plain language. My other advice is to start shooting RAW and in Manual mode right off the bat. The faster you learn how to control the shot and final product yourself the better off you'll be.

I'll give a different perspective...
Don't start worrying about RAW and manual right off the bat unless you learn better that way. RAW vs. JPEG is irrelevant in all sense of the word when it comes to photography. Editing, yes, but photography no. I almost rarely use RAW as well...only for the most important shoots. Everything else, I just use JPEG High. I get plenty of DR and flexibility in editing and don't have to worry about storage issues (and speed).

Also, manual mode is personal preference. To this day, I use manual mode maybe 10-15% of the time (mainly off camera lighting, panorama shots, or areas where I need to keep the exposure consistent). I'd say learn ALL the modes (P,S,A,M) and how they affect your shooting style and situation.

You learn how to make the tool record your final vision. Once you understand what you need the camera to do to capture the scene as you see it, then you can start trusting the camera to make certain decisions for you through Av and Tv mode. Beginners make a lot of mistakes (hell even more experiences photogs do too) and a RAW workflow gives you more flexibility to correct those mistakes in post. Just my $.02

Aperture controls depth of field. Bigger apertures (smaller numbers) give shallower depth of field, which is the area in the image that's in focus, while a smaller aperture (bigger number) gives a wider depth of field. Distance counts too, the closer the object you're focused on the smaller the depth of field. Basically this lets you decide what and how much of your image is in focus.

Shutter speed controls motion. A faster shutter speed (1/250, 1/500, and faster) will freeze motion. A slower shutter speed (1/10, 1/4s, etc) will allow moving objects to blur and can also cause blurring due to camera shake. Moderate speeds in the 1/30-1/125 range will freeze most people movements but maybe not wind blown trees or fast moving objects.

ISO controls light sensitivity. Bright sun means you have lots of light to work with and can run a low ISO, dark rooms require higher ISO to be sensitive enough to capture an image at workable shutter speeds and apertures.

Umm... no. Aperture and shutter speed do not control how light sensitive the sensor or film emulsion is, they only control how much light is let through the lens.

Umm... no. Aperture and shutter speed do not control how light sensitive the sensor or film emulsion is, they only control how much light is let through the lens.