For the first 6 months of life, we recommend that you place your infant on his or her back to sleep. Try to place your infants head in a differnet direction on alternate days to avoid getting a flat head on one side. The ideal location for sleeping is in a crib in your room. Avoid putting extra soft material in the crib such as comforters, bumpers, stuffed animals etc. as they can increase the risk of SIDS (sudden infant death syndrome). Also try to avoid having your infant overheat. Second hand smoke contributes to the risk of SIDS (as well as many other health problems).
The Canadian Paediatric Society has information on their website about a variety of topics including safe sleep, preventing flat heads in infants who sleep on their backs, the user of pacifiers and many other sleep related topics.
After 6 months, you may want to try to train your child to fall sleep alone. We recommended the book Solve Your Child’s Sleep Problems by Richard Ferber.