Aren't ACDs wonderful. How lucky you are to have a lady to love and be loved by. I know that you feel that you are blest by having the chance to share your life with such a wonderful companion.
I am sorry that I did not get a chance to answer your post sooner. Life has been a bit hectic around here lately and I wanted to devote the time to you. I want to be able to answer your questions and provide as much guidance as possible. I hope that I don't overload you with information, but I want you to be aware of the ramifications of breeding. To be honest, there are times that I wish I wasn't a breeder.
Now for the concerns:
How old is your bitch? No bitch should ever be bred prior to two years of age. Also if she is older (5 or 6) and has never been bred, you are taking even greater chances of losing her and/or the pups (there are many health risks involved with pregnancy and whelping, more about that later).
When considering a breeding you need to be aware of your dog's strong and weak points as it compares to the breed standard. When choosing a mate for your dog you need to choose one that will hopefully correct her weaknesses with his strengths. For example: the standard calls for an "otter tail". This is a tail that comes down to the hock, is broad at the base and tapers to the tip. Let's say that your bitch has a long, skinny tail, you would want to breed her to a dog with a wonderful tail. This same thing would hold true for a good head, length of back, coat, bone structure, etc. Another very important thing to look at is the pedigrees of both dogs . It is very important to make sure that the pedigrees are compatible. You can run into some terrible health and conformation problems if the wrong dogs are bred to each other.
Photos here are the property of this website