First Things First - Get a Helmet
Tt's simple, Get a helmet and wear it.
Modern helmets are comfortable, stylish and every mountain biker wears one. You can go to your local bike shop and they will be happy to help you pick one out that suits your needs and budget.
Some other safety equipment and accessories that I recommend are cycling gloves (I prefer the full finger style), some sort of hydration system (either a water bottle or a hydration backpack), eye protection or sunglasses, bike shorts with extra padding where it counts, sunscreen, and a shirt made from quick drying material.
Continue through the following exercises.
Pedal PlayPedal Play - Get Used to Your Pedals
Practice removing your foot from the pedal. Do this first while sitting on your bike with one foot on the ground. Then move on to releasing and replacing your foot while pedaling around. Beginners with toe clip and clipless type pedals will want to spend a little more time here.
Sit and Spin For Proper Fit and Position
Sit on your bike and pedal around.
Your arms should remain slightly bent.
Your seat height should be adjusted so your leg is about 70 to 90 percent extended at the bottom of every pedal stroke.
Keep your body loose and relaxed.
There is never a situation when you should have your knees or elbows locked.
Shifting Gears - Learning
How and When to ShiftGet comfortable with shifting the gears on your bike.
Higher gears are harder to pedal and will go faster while lower gears are easier to pedal and help you get up hills.
Next, try to get used to what gears you need to be in to comfortably go up different pitched hills.
As the hills get steeper,
it is best to shift before you get to the hill rather than while you are on the hill.
Stand and Coast - Get to Your Correct Body Position
Spend some time coasting while standing on your pedals without sitting on the seat. Keep your arms bent and don’t lock your knees, put your pedals at the 3 and 9 o’clock positions (horizontal). Next, experiment with shifting your body towards the rear of the bike.
You will want to be in this rear shifted standing position when you coast over obstacles or when the trail gets rough. You should be standing on your pedals with your knees bent and your seat should be between your legs. This is your primary standing position.
Pedal Up - Learn to Pedal While StandingGet comfortable with pedaling while standing on your bike.
Lift yourself off the seat, stand on your pedals and
crank them around.
Try this in higher gears on the flat and
in lower gears on the hills.
Down a Curb - Do the Drop
Find a curb where you can easily get to the upper level.
Stay in position and absorb the drop with your arms and legs.
Try this at different speeds until it becomes comfortable.
Practice standing and coasting straight off the curb from the upper level to
the lower level at a moderate speed.
the lower level at a moderate speed.
Stay in position and absorb the drop with your arms and legs.
Try this at different speeds until it becomes comfortable.
Up a Curb - Get Over It
Approach straight at a curb in your primary standing position from the lower level at a slow to moderate speed. Shortly before you reach the curb push down towards the handlebars to get some spring from the front tire and then quickly push your body up from your hands and pull the handlebars up lifting the front wheel up just in time to reach the upper level of the curb. Next, quickly lighten your weight on the pedals if you can and allow the rear wheel to come up to the top of the curb. Absorb any bump with your legs and continue on forward.