It just takes practice. I'm in the same boat. Just got my good camera a month ago, so I'm learning all the manual settings. One tip I found very helpful is to use the "burst" mode or whatever it's called on your camera. This is where the camera will take several pictures as you hold the shutter down. Often you end up with a blurry picture when you press the shutter, so if you use the burst and shoot 2-4 pictures, one of them will end up a keeper.
Also, I've been told that the book Understand Exposure by Brian Peterson is very good. I haven't had a chance to check it out yet. And I think someone on here mentioned a good website as well:
PictureCorrect Photography - Digital Camera Reviews, Tips, and News