lawrence, Have Faith! It will happen, you will get better by being here and practicing.... The more you shoot, the more you will learn... You already have a wealth of tips and motivation and I will share a couple thoughts.....
The obvious...
Learn your camera!!! Know what each control does and how it affects your images... especiallty learn the focus modes and holding rock steady.. (hand, tripod and shutter speed)
You must learn the exposure triangle and how changes affect your image... plenty of resources for that.... and practice, change settings and try to achieve affects (or at least see what happens if!)
The hardest part is learning to "see" with a photographers eye... I still have a lot to learn, but looking at what others have done and trying to replicate something similar will cause you to start seeing more and more... Study others photos that you are impressed with and practice.... and practice and practice... The more you shoot, the more you will realize what works and doesn't for You. eventually you will start seeing things that you never saw before...
Composition... learn the basics and practice them... (rule of thirds etc). Under Tutorials, Horoscope Fish has a 3 part thread there that is excellent...
As many have already said, do not worry about throwing stuff away... we all do it and that includes the good photogs here. Study your own shots and ask what was wrong, the composition, focus, exposure (or in some cases all of the above

) Learn from analyzing your own work. Post up in the feedback system and get help from the users....
Understand that many photos are enhanced via post processing to get the comp better (crop) and improve the POP...
Lots to learn, but all of it involves practice... shoot shoot shoot... The 365 is a great tool as mentioned... another is spend a day shooting using only one lens for all shots (or one focal length) You will have to adapt a lot more and its a fun challenge!
I have a long way to go and learn everyday, but I owe it all to the people, tips and phots I see here... I have a D7100 now... but also used a 5100 as you and I still use it today....
have fun!!! take a break when you need then come back fresh and shoot more!!!
Pat in NH