The best way to start is to go to some shows, be patient stay out of the way but spend time in the pen area when the judging is not going on and see if you can sort out for yourself the breeds that you think you may enjoy. When you see an opportunity speak to the breeders and get as much information as you can. Take your time, the research is half the fun.
Get a the standard of perfection and begin to get a picture of what the good ones look like, ask questions, ask more questions and pay attention. Breeders dont (in general) mind helping folks that pay attention and act on good information. Most breeders have little patience for those that simply want to know where and for how much they can buy some birds.
Start with only a breed or two and get to know what the good ones look like. In the beginning they all look alike but after a while you can see the top ones and the bottom ones at a glance.
My best advice is to make the learning a significant part of the experience.
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