Dogs' wild relatives live with some strict rules. Their pack has a leader, and each dog knows his place in the pack and follows the rules the social structure demands.
For your dog, your family is the pack. And you need to be the leader of that pack if you want to live peaceably with your dog. That doesn't mean you have to physically dominate your poodle. It does mean that you control the resources. That is, you're the one who gives her food and treats, decides when she goes out, and so forth.
Reinforcing Your Role as Leader
Use your everyday dealings with your poodle to reinforce your role as his leader. Ask him to sit before putting his food bowl down or before you give him a treat. (Think of it as teaching a child to say “please.”) Take away the toy he's playing with every now and then, and replace it with another one. This teaches him that you control his toys as well.
In your effort to establish yourself as the leader, you need to call the shots. If your poodle demands your attention, for example, turn the tables so you're in control. If you don't have time or inclination to lavish attention at the moment, ignore your poodle's prodding. If you don't mind giving him attention at that moment, ask him to do something, and use the attention as a reward.
If your demanding poodle gets underfoot while you're trying to accomplish things around the house, put him in his crate for a couple of hours (and give him something to do in there).
Leadership isn't necessarily going to be an issue between you and your poodle. Some dogs are born leaders and need more reminding than others that you're actually in charge. Others are happy to take a more subservient role. Whatever type of poodle you have, she'll benefit from your consistent show of benevolent leadership.
Forget About Alpha Wolf
Bear in mind that the old-fashioned notion of dominance when it comes to the relationship between people and dogs is falling out of favor with progressively minded behaviorists and trainers. That theory, popularly espoused in training books by the monks of New Skete, among others, would have you physically roll your dog onto his back in what's known as an “alpha roll.”
The theory behind this practice is flawed for a number of reasons. It's dangerous, for one. (You put your face in very close proximity to the face of the dog.) It's not even sound theory, since wolf experts report that alpha wolves don't actually do this to their subordinates. (Rather, it's the wolves that are trying to work their way up the pack hierarchy that practice this behavior.) Finally, it feels really bad to do this to your dog.
Scruff shakes (where you grab your dog by the fur on either side of his neck and shake him), another method encouraged by those who feel that you have to physically show your dog you're the boss, are also unpleasant and unnecessary.