Hi, I'm FAR from pro - just an amateur photographer who has lots of fun with photography. But i'll try to answer anyway. 
I'm a time-starved student myself so I haven't got much time to read up on technical stuff about photography...
So I'll just tell you what I do know as someone who lugs around and has fun with two digital cameras (one superzoom and one micro four-thirds) every day.
General advice first.
- Be sure to check out this forum section.
http://www.clubsnap.com/forums/forums/8-Newbies-Corner
- The key things to know about photography is aperture, shutter speed and ISO (light sensitivity).
I believe this forum thread does a very good job of explaining what these are:
http://www.clubsnap.com/forums/threads/309544-Photography-Notes-For-Newbies
Once you understand the fundamentals, you'll be able to experiment and have fun.
Also, when you shoot more, you'll find out the type of photography you're more inclined towards: landscape, architecture, nature macro, portraits and so on.
So if you want to see yourself improve so as to motivate yourself to keep pursuing photography as a hobby, it might be good to focus on what you like first, by reading books (or online resources) on that specialised type of photography, and putting it into practice.
Then, as you progress further, you might want to explore the other types of photography.
Now, addressing your questions...
You said your photos are "really not good enough." Sounds like you already have a benchmark in mind, like you're comparing yourself against some ideal, or someone else's photographs.
You might want to look at photo books and so on, pick out the photos that appeal to you, and then think about how you can achieve that.
Don't be too hard on yourself, a hobby has to be pleasurable after all. 
About the too bright and too dark part, you can adjust the exposure value (dslrs usually let you change that very fast), or apeture, shutter speed and iso to make sure there's a balance.
There are also some situations when the lighting is not as you want it, but is by no fault of yours. One situation I can think of is back-lighting, when the sun is behind your subject. There are ways to go around that (HDR?) but I'm not sure about that...
As for the focus on target and blurring of background, I believe you're trying to achieve a shallow depth-of-field.
It is usually achieved by using a wide aperture (eg f1.8 - the smaller the f number, the wider the aperture).
But it can also be achieved when you change your distance from the subject, be it you walk physically closer/further, or you change the focal length of the lens. I think the closer you are to the subject, the less depth of field there is.
My ultimate advice would be to bring your camera out with you whenever possible.
There's a saying that goes "The best camera is the one that's with you."
And be curious about and sensitive to your surroundings. Photography is a lot about having a good eye.
Have fun. 