This is from the point of view of a potential buyer. It is mostly what *I* would look for.
A breeder who will be there to answer questions after you take the rabbit home. This would be really important for a first time rabbit owner. Just having someone who will answer questions about food, housing, grooming and other aspects of the care of the rabbit. Even if you don't have any questions, it is still good to know they are avaliable if you need them.
A breeder who knows the breed(s). If I have a question about that breed or a specific care aspect of the breed, they should be able to answer it. If an angora breeder doesn't know about grooming, they probably aren't the best out there. They should be upfront about any issues with the breed could have. If you are looking for a show rabbit, they should also know the breed standard and be able to help you with that.
I would prefer to go to a breeder who shows the rabbits. While there aren't a lot of shows around here, they should do what they can, even if it is only 1 or 2 a year. There is no way I would buy a show rabbit form someone who doesn't show. If you don't show, it is hard to really know what show quality is. If you aren't looking for a show rabbit, then this doesn't really matter, but to me is shows commitment and a purpose for breeding.
I would like to see where the rabbits are raised if at all possible. I do realize that some breeders don't like to have strangers in their rabbitry, but I would be wary of someone who didn't at least let me come to their place. If they insist on meeting in a parking lot, I would not buy from them. While there are times that meeting at the breeders is not possible, I still like a breeder that is willing to let me see. Being able to see the parents of the rabbit as well as other rabbits is good to be able to know more about the practises of the breeder. If you meet off site, they will probably only bring the best or cleanest rabbits. If you meet at their property, you can see all the rabbits.
A breeder who is a member of rabbit clubs is a plus. ARBA would be a good one along with a local club. A breed club can also be good.
A website is nice. I can see what their rabbits are like and what they breed (breeds, colours etc). You can also see how much they breed, and get to know a bit more about them. A website gives me an overview of the breeder and I can make some basic decisions on if I would go to them from it. If I don't agree with their practises, then I don't have to go any further. Even just knowing where they are located and what they breed can be a huge help.
I basically look form a knowledgeable breeder who is open and honest. I also like one who is involved in rabbits and rabbit people. Someone who will be there to answer questions and possibly take the rabbit back or help you re home it is a huge plus. I want a breeder who cares about their rabbits and where the rabbits go.