Of course, to increase the appeal and nuance of your stories, you'll want to layer in more detail as your skills allow it. A good "first steps" book to study is DRAW 50 FAMOUS CARTOON CHARACTERS
, by Lee J. Ames. Ames's books show how to draw characters beginning with simple shapes and adding more complex details. This book in particular is useful because the characters are familiar and they range from the simple (The Little King, Felix the Cat) to the complex (Blondie, Flash Gordon). After working through these, you could move on to designing and drawing cartoon characters of your own.
From there, the next step would be realistic draftsmanship. The best book to start with here is DRAWING ON THE RIGHT SIDE OF THE BRAIN
, by Betty Edwards. Edwards teaches techniques that artists use for overcoming the mental obstacles to realistic drawing. I plan to cover this in a future Toth article, but for now, in brief: the system our brains use to handle imagery is good for storing and recalling ideas, but bad for drawing. It's like a biological version of the the difference between hi-res jpegs and low-res bitmaps. Typical thinking works best with "lo-res," but realistic drawing requires "hi-res," so artists must use certain thought tricks to switch their thought mode over to the "hi-res" way of thinking. This may sound complicated and Jedi-like, but Edwards explains it well, and it's frankly crucial to realistic drawing. You can see the effectiveness of her techniques in this "before and after" gallery
of her students' work, spanning a five-day period. Using Edwards's techniques, you can begin drawing by observation (drawing objects you see before you, or in photos), which is every artist's most valuable calisthenic.
After working through those books, you'll be in a good position to absorb what Loomis has to offer. His books (especially FIGURE DRAWING FOR ALL IT'S WORTH [anatomy], SUCCESSFUL DRAWING [perspective], and CREATIVE ILLUSTRATION [the best one, about picture-making in general]) are great (and back in print!) and should provide a sound foundation for everything else your comics might need. If he's still a bit beyond your grasp, I recommend any of Jack Hamm's excellent how-to books, which are simpler but top-notch, and cover similar ground.
But above all, keep cartooning. Pick the crucial story moments, pick the props and body parts that illustrate them, and jot those down.