Oh where to start....
First off, you want to leave your baby rear facing as long as possible. He is nowhere near ready to forward face at 10mos old, so don't bother starting that transition. The old recommendations of 1yr/20lbs are ancient recommendations, and they have changed. the AAP recommends rear facing to 2 and 30lbs, or to the limits of the convertible car seat. Every car seat manufacturer recommends using the seat to the rear facing limits. THe Triumph (Its Evenflo, not Graco) will rear face to 30lbs, but it has an EXTREMELY short shell that is outgrown before age 3 with most all children. Please google EXTENDED REAR FACING for more information. My youngest rear faced until he was 33lbs, 42" tall, and 3yrs old. He was perfectly safe and comfortable. Do some research, google EXTENDED REAR FACING and JOELS JOURNEY. Bed, Bath, and Beyond has the Graco MyRide 65 for $99 right now, it will rear face to40lbs, forward face to 65lbs. Its a GREAT comfortable seat with amazing side impact protection, and at this price its a total steal! Target carries it for $122 right now, and Wal MArt has it for $120 right now.
For your 2yr old, he could easily still be rear facing too at only 30lbs. The Graco MyRide65 would be perfect for him as well. My 4.5yr old still easily fits in this seat rear facing, and he's 42" tall and all torso. If you want to continue ot forward face this child, I would recommend the Graco Nautilus ($150). It will harness to 65lbs (most kdis can use hte harness to age 7 in this seat) and then it becomes a good high back booster seat to 100lbs, and eventually a no back booster. This is a great value, truly the last seat he will ever need, and it makes a good booster seat, unlike some of the 3-in-1 seats like the Alpha Omega, which failed miserably as a booster seat over and over again. STEER CLEAR of the Alpha Omega, Eddie Bauer 3-in-1, safety 1st 3-in-1, etc. They are a total waste of money, and they make horrible fitting booster seats.
So what I would recommend is you do some research on Extended rear facing, and get your baby the Graco MyRide 65, and rear facing him until hes at least 2yrs old. He could use this seat then forward facing until hes 5/6, and then could easily move to a simple high back booster seat until he's 4'9" and can ride in the adult belt.
For your 2yr old, if you want to rear face him again, get the MyRide for him as well. If you want to forward face him still, get the Graco Nautilus. This seat will harness him until he's 6/7yrs old, then he can use it as a booster until he's 4'9" and can sit in the adult belt alone.
Some more things to consider when using a car seat-
Only use LATCH OR the seat belt, you cannot use both together. One or the other, neither is safer than the other, use whatever gets the best install and is easiest for you. LATCH in most vehicles cannot be used after 40/48lbs, read your vehicle manual. AFter 40/48lbs, you MUST USE THE SEAT BELT to install the seat.
When rear facing, the harness should come from at or below the shoulders. Rear facing is outgrown when the child has less than 1" of hard shell seat above the head, or when the rear facing weight limit is reached. Long legs are NOT a problem and there has never been a documented case of broken legs while rear facing (however one of the most common injuries in forward facing children is broken legs, even in minor collisions).
When forward facing, the harness should come from at or above the shoulders. Forward facing seats are outgrown when one of three things happens; the child goes over the forward facing weightl imit, the shoulders go over the top harness slot, or the ears are level with the seat back.
Chest clip is just that, a chest clip. It should be level with the armpits, not down by the belly.
Harness should lay flat to the body, no twists. It will not work properly if its twisted up.
No bulky clothing, winter jackets, buntings, or bundle me covers in the car seat! These will re route the harness, make the harness too loose, and subject your child to ejection or severe injury in a crash.
Children should remain rear facing as long as possible beyond 1yr. The AAP recommends children remain rear facing until at least age 2 and 30lbs, or until the rear fcaing weight limits of the convertible seat are reached.
Children should remain in a 5pt harness until a BARE MINIMUM of 4yrs AND 40lbs. Children under 40lbs and 4yrs old are 75% more likely to suffer abdominal nad head injuries in a crash if they are in a booster seat vs a 5pt harness.
The current laws (1yr and 20lbs to forward face, 4yrs and 40lbs to boosteR) are BARE MINIMUMS. Your children (not you specifically, you as in everyone reading this) are worth more than the bare minimums! Its your job to install the seat properly, use it properly, 100% of the time. Just having it in the car is not enoug hto protect your child in a crash. It has to be used 100% properly. You may only need yoru car seat one time, but that one time you need it 100%, and your childs life depends on it.
Some things to google- EXTENDED REAR FACING, JOELS JOURNEY, www.carseat.org, www.safekids.org, www.seat-check.org
I also wanted to add, that neither of my children have suffered from being safe in the car. My oldest was in a harness until he was 7.5yrs old, 60lbs, and 52" tall. His self esteem is very much in tact because we taught him the importance of safety, he knew why he was in a harness, and why he remains in a booster seat to this day. Most of a childs self esteem comes from their parents, so if mom and dad are calling car seats 'baby seats' or making them seem stupid or unnecessary, the child will think the same. When you know better, you do better. Its proven children are safer rear facing, its proven children are safer being harnessed as ong as possible, and its proven that being in a booster until the adult belt fits properly is safer. Why compromise your childs safety, especially that of a toddler or elementary age child, because a parent doesn't think its 'cool'? It doesn't make sense. putting your child is the car is the single deadliest thing you do daily, why risk it?