One of the most important things you can do in terms of getting your newborn to sleep better is to establish a routine, and to stick to it. The more regular your baby's sleeping hours are, the more likely he or she will be able to sleep solidly throughout the night.
As soon as possible, try and establish a sleeping pattern with your newborn that mimics the one in the rest of the household - in other words, one in which most of the sleeping is done at night.
If you find that your newborn is sleeping-in because of being up late at night, rouse him or her at the time when you normally get up. By doing this it's more likely that your newborn will be tired and sleep in the evenings.
On a general level, there will be no way to avoid the fact that your baby's sleeping habits are going to be irregular, and there are, of course, going to be times when the baby simply wants to be awake when the rest of the family wants to be asleep. Over time, however, your newborn will begin to adjust to your family's regular sleeping habits if you instill in him or her at an early age a sense of routine.
A baby, particularly when he or she is very young, is heavily influenced by these routines. As much as possible, you should resist the temptation to let the newborn arrange his or her sleeping habits. The baby, of course, will want to sleep a lot -- which is fine -- but don't let the baby sleep too late into the morning. By establishing a routine with your baby from a young age you will ensure that the transition into more regular sleeping habits is both a quicker and smoother one.