
First you need to establish if your bitch really should be bred from at all. As Cockers are a numerically strong breed there are plenty of well bred and not so well bred cockers around.
Ypu need to ask yourself some questions the link will give you some food for thought
http://www.k9web.com/dog-faqs/breeding.htmlIf ytou decide that you will go ahead, having done all the relevant health checks using the official schemes, waited until she is two years old, and you are syure that you will be able to be responsible for the pups for life, and take back any that find themselves in need of rehoming, then I would join some breed clubs, go to shows and learn about your bitches pedigree and the dogs in it, and the same about potential partners. If her breeder is a repoutable knowledgeable peron in the breed you can do no better than seek their help and advise. If they are not then the chances are your bitch is not of the quality that will improve the breed by producing the next generation.
Hope that helps.