E.M.
There are infant car seats, often called infant carriers, that are sometimes bought as a travel system but can be purchased alone. These seats rear face only, and go to 22, 30, 32, or 35 pounds depending on the make/model. The 22 pound ones are outgrown rather quickly, around 6-9 months for some children. The higher weight ones can be used until 15-18 months for an average sized child. At the time the infant carrier is outgrown, you'd need to purchase a convertible car seat. These car seats rear face, and then you can turn them so they forward face. A child needs to remain rear facing for a minimum of 2 years. The American Academy of Pediatrics recommends a minimum of 2 years, or until the rear facing car seat is outgrown-- which can be 3-4 years or longer. Rear facing is 500% safer for children 4 and under and can reduce the risk of serious death or injury in an accident by 70%. It is absolutely necessary that you do not forward face your child prior to at least 2 years. But like I said, that's just a minimum. The longer the better! I hate a 4 year 8 month old daughter that is 42 inches tall and weighs 36 pounds who rear faces in a Graco My Ride 65 half of the time- her other seat is a forward facing Graco Nautilus).
I urge you to go to www.car-seat.org for car seat advice and suggestions. Also, please take a look at the following information for rear facing:
http://aapnews.aappublications.org/cgi/content/full/30/4/...
http://www.youtube.com/watch?v=kvyIv9QVRBE (my little ones are at :47 seconds)
http://www.kyledavidmiller.org/car-seat-safety-rear-facin...
You can also skip the infant carrier and just use a rear facing convertible car seat, if you wish. There are a few of these seats that are NOT good for newborns though, and this inclused the Safety 1st Avenue, any Britax convertible seat, and the Safety 1st Complete Air. These car seats don't have a low enough harness slot for the harness to be below a newborns shoulders. Sometimes these seats aren't grown into until a child is 4-9 months old, depending on their size.
Please come visit us over on www.car-seat.org!