How to do a Forward Roll
The first roll you’ll be learning is how to do a forward roll. This is also known as a front roll or somersault. In it you go over your head and roll around the mass of the back in line with the spine. It is a straight forward roll.
To start off with you’ll want to start in an squat position. Place your hands on the ground and tuck your head in so that your chin is near your chest. The first area that should touch the ground is near the back of your head, the neck and shoulders. From here you tuck tightly into a ball and roll. The momentum should carry you forward and you should easily be able to come to your feet.
When you become proficient in this basic move you can try the same move from standing, while walking or even running. You can do the roll without the use of the arms and in many other ways.
How to do a Back Roll
Back rolls are very similar to the forward roll. This roll takes you backwards over the back, along the spine into an upright position.
The back roll is much harder for many people as they have a weak neck which cannot take the strain of going over backwards. If your neck hurts when you do this move (assuming you do not have serious cervical issues) you need to work on building up that strength. I suggest the wrestlers bridge to start with.
Assuming that is not a problem for you, lets get started on the technique. Take the full knee bend position so you can start low to the ground. Sit back breaking the fall with hands. Start rolling backward, bring hands up over shoulders, palms facing backward, fingers pointing toward shoulders. It is important to keep the head tucked so that it will not be bumped when rolling back on the shoulders. Roll back placing hands on the ground, giving slight extension of the legs backward after the feet are well over the head, push hard with hands so as to take as much weight off the head as possible. As the head comes through, bring feet down well tucked under, coming to a squat position or a full stand.
Just like in the front roll once you can do this starting position you can do the back roll from a stand, walking backwards and in any number of other positions.
The safest roll in most cases is the shoulder roll covered in How to Roll. But you should know how to do all manner of rolling including those not covered here. For more variations and tons more stunts you should check out Tumbling Illustrated. It will further help you with these basic rolls as well as much more advanced tumbling stunts.