1. KNOW YOUR EQUIPMENT
It may sound very basic, but if you don't really know how to use your camera (and other equipment such as flash) then you are facing an uphill battle and will miss those once in a lifetime shots. Get to know how to quickly change the basic settings and life will become much easier as instinct kicks in.
2. LEARN THE BASICS
Get to learn about the basic aspects of photography including why there are different apertures (f-stops), lens focal lengths, and shutter speeds. Using a camera is all about controlling light and these are basic things you need to understand. (See my TIPS section on this site). You also need to understand the basics of composition and depth of field. Learn techniques on how to hold a camera steady and techniques on how to pan a camera to follow a moving subject.
2. GET AWAY FROM AUTO or PROGRAM MODE
Auto or Program Modes are the lazy person's way to photograph and you will not learn much except how little control you have over the final result. Once you learn to shoot in Aperture Priority and Shutter Priority then control of the image is up to you. Auto or Program modes rely upon the camera technicians trying to second guess what sort of photo the camera is trying to take. They know as much about that as you know about what car they drive, so get to learn the other modes on your camera.
3. PRACTICE & EXPERIMENT
Practice, practice, practice. You can't learn to drive a car or play a music instrument after a couple of minutes. Photography is no different. You need to take lots of photos and examine them to figure out what (if anything) went wrong. Experiment with different techniques that you read about to make your photos more interesting. I own lots of books on photography and would recommend books Michael Freeman or Tom Ang, especially their "masterclass books". There are also plenty of useful articles and videos on the internet. Most of all, try to enjoy yourself. It can be difficult and daunting at first, but after a while as begin to pick up good techniques and understanding, things will click into place and you will soon be taking good photos.