215Talari, The LATCH system is pretty straight forward which is great. Make sure that it is secure and doesn't have side to side movement. The back should be at approx. a 45-degree angle. The most important thing is to have the shoulder straps go through the seat below the height of the shoulder. In the event of a collision, the straps below the shoulder of a rear-facing seat prevent the child from sliding up on that 45-degree angle. If they are above the shoulder height in a collision, the child will slide upward then have a sudden stop when they impact the strap, potentially compressing the spine. Make sure the straps are tight! If the child is wearing a jacket in the morning and a light shirt later, adjust the straps. The device that connects the two shoulder straps above where they lock to the base, should be positioned at the chest. I use the armpit as a good location. Keep him in the rear-facing position until he is a year old. Some people change when they feel their child is "big enough". It has to do with the child development (bones, tissue, organs) and not size. When you change to a forward-facing seat, let me know because everything is different.