Hi Coach,
You're doing okay for first shots on manual! Really, I think my first ones were completely black.
You said you ordered Understanding Exposure (IIRC), so when that comes... definitely read it. It will help loads.
Real quickly though....
Manual mode does not mean manual focus.
Here's a quick-and-dirty run-down of the different exposure modes:
Manual: you pick the aperture (also called the f stop), the shutter speed, and the ISO.
Aperture priority (A): you pick the aperture and the ISO. The camera picks the shutter speed.
Shutter priority (S): you pick the shutter speed and the ISO. The camera picks the aperture.
Program (P): you pick the ISO, the camera picks the aperture and shutter speed.
In all of those modes, you can either manually focus or let the camera focus (auto-focus).
If you choose auto-focus, that doesn't mean you are just stuck on letting the camera decide WHAT to focus on, though. There are different auto-focusing modes, just like there are different exposure modes.
For focusing....
If it's not already, try putting your camera into single servo focus mode (AF-S). You will then be able to use the mutliselector (squishy round button on the back of the camera that has arrows on it) to choose which focus point you want the camera to use. Once you get the focus point over whatever you actually want the focus to be on, you press the shutter button half-way down--this will let the camera lock focus--and then when you are ready, press the rest of the way down to take the picture.
Once you push that shutter button half-way down, the focus WILL lock on whatever you have your selected focus button over. If you keep the button half-way pressed, you can shift the camera slightly and even if your selected focus point is no longer over the subject you are choosing to focus on, you can still press the shutter button the rest of the way in to take the shot and your subject should still be in focus.
This technique is called focus-recompose. So something you might want to try is just using the center focus point, get it over what you want to focus on, press the shutter release button half-way, compose your shot the way you want it (keeping the shutter release button half-way depressed), and then press the shutter release button the rest of the way down.
What lens were you using?