Welcome!
You've come to the right place, and you're asking the right questions! It's quite wise of you to look for a puppy that's healthy, stable, and a real member of the Doberman breed. Read up on what makes reputable breeders "reputable." Good breeders are custodians of the breed. They don't breed their dogs solely to make puppies for prophet; they care about working toward the most intelligent, loyal, and true-to-form member of the Doberman breed.
In order to prove that their animals are great representatives of Dobermans, they put them through different physical and mental tests. These can be traditional conformational dog shows, athletic events, or feats of mental prowess and obedience. The best members are selected for special recognition, giving them merits of achievement, or titles. These are the winners.
Like others said, if a breeder tells you that titling is not important, they are wrong. In order to be a good representative of the Doberman breed, this needs to be shown and judged by an expert in the breed. Remember that the Doberman is a breed developed by human involvement like all dog breeds are, and it is our duty to protect it and better it. To let dogs fall ill to horrible diseases and temperament problems is a travesty for us as custodians of these animals we created.
That said, these great breeders often have puppies in litters that are not destined for the show ring, but they are still fabulous representatives of the breed. These breeders give a lifetime of support and advice, a healthy dog (though this is never guaranteed), and a great start in life and a background to prove it. It usually takes a longer period to get one of these puppies, and the breeder will want to develop a relationship with you, but this is all worth it.
Anyway, stick around, and read as much as you can. There are some amazingly knowledgeable people here at your fingertips!