What type of carrier should I use?

Baby Bjorn. A baby carrier that carries the baby on your chest allows visual contact with the baby and keeps the baby off the back of its head reducing the risk of flattening of the back of the head.
Experiment. Experiment with a couple and see what you and your baby prefers. Some carriers come with an infant insert which is handy. Infants typically face towards you and as they get older and gain control of their head and neck they are turned around to face the world. Some popular carriers are ergo, baby bjorn and the moby wrap- each holds the baby in a slightly different position.