I just love picking out the fabrics and colors of a new project. Many of my friends do not.
The way I started was to pick a focus fabric first and then go from the colors in that. I have worked lots with the color wheel in my past life, so I think that has helped me some with colors for quilts. Many times, when friends are with me, they kind of look at my choices and say, "are you sure you want to put that in?" They are usually surprised how it turns out when I'm done.
It does take time to get the feel of it. If you're really not sure, just ask someone in the quilt shop and they will help. Even other customers will chime in. It doesn't hurt to have more opinions. Relax and enjoy the process, and don't be afraid to ask for help.