Well, when I was starting out, I was taking similar shots and worse. Technically these are all fine (#2 appears to be a little underexposed). I might even go so far as to say that #4 is well composed. But they don't show creativity, tell a story, or any other such things that a great photo needs.
It's tough to make any specific recommendations as far as these images go, so I'm going to recommend you read some good books. The first is cheap as dirt.... $.51 used on amazon and an EXCELLENT book on composition and creativity.
Amazon.com: The Art Of Seeing: A Creative Approach To Photography (9780879857479): KODAK: Books
The second is Michael Freeman's "The Photographer's Eye"
Amazon.com: The Photographer's Eye: Composition and Design for Better Digital Photos (9780240809342): Michael Freeman: Books
These books are full of great photographs and ideas on how to create them.