It's hard to start out without some help - especially in a breed that requires grooming. I went to my first show with a brush and a spray bottle and a sense of foreboding panic. :) I lucked out that a couple of very nice people held my hand and kind of walked me through what to do. My first time in the ring was under a VERY noteable and impressive breeder/judge. He took one look at me and asked "first time in the ring?" :)
I think any breed can be competitive and mean. Shelties as a breed have a reputation for being really snobby and hard to break into. I've been REALLY lucky. I have a friend who can't seem to catch a break - so developing a successful breeding program has been hard for her. And she doesn't tend to get a lot of positive feed back from a lot of people. I just happened to get a couple of my earlier dogs on co-ownership from a couple of very nice breeders who have been kind enough to help me out. I always marvel at how some exhibitors will do everything to give themselves and edge in the ring. I tend to prefer the outlook that if my dog wins, I want it to be because he was the better dog (quality, grooming, AND handling).
But my first show dog has been a REALLY tricky one to show... he's physcially gorgeous, but very sensitive and tends to get stage fright. He shows great under judges who don't like his type :) but acts like a freak whenever he's under a judge who would put him up if he just acted like he didn't need to see a shrink. :) I swear HE KNOWS which ones like how he looks... :) I've learned a lot about handling from working with him. It's made showing my "newer" show prospects a lot easier and more fun.
So having a great dog is 1/2 the battle. Having skills in grooming and handling is the other half. I'd try and find a breed club - or just go to a couple of shows and try and find someone who wouldn't mind giving you some guidance. Honestly the best way to find a breeder if you want to show is go watch a couple of rings, meet some people and see who has the type of dog you want and the personality that you feel comfortable working with.