Being a lineman in football is not an easy task. Follow these steps to become a successful player.

[edit] Steps

Be ready, it will be a challenge.
Get into shape. Try various ways of working out and try to use all of your muscles.
Learn lineman techniques and ways to practice.
Find a friend to join or help you.
Do neck bridging. This can prevent you from breaking your neck.
Run every day; try at least a mile. You will want to quit, but whatever you do, don't.
Do a lot of sprinting exercises.
Join a team at school. This may be one of the hardest things you have done so be ready, be prepared, and be in shape.
Line up on the center as you normally would, unless your coach tells you otherwise.
- If the center's shoulder is slanted down because his arm is going to snap the ball, you should, after the snap, grab and pull that shoulder down and get in the backfield.
If you have a lot of speed and you are skinny, take a jab step to one gap and quickly dart to the other (step to left dart to the right). This works great against a slow lineman.
The Swim Move: This move is done by basically swimming though the offensive lineman i.e. you're going to go through the right side of the center. Slam your RIGHT hand on your RIGHT of the centers shoulder pads and swing your LEFT hand over him.

[edit] How to be Successful

Now to the real stuff. Lifting weights is the best thing. You can't look like a wuss. Bench, Squat, Clean and Snatch are the primary lifts. There are variances to all of these which you should do. Also try a sport called Strongman. It helps a lot to have this extra strength and you will find it will be a whole lot easier when you have brute strength behind you.
Run. Don't limit yourself. Run until you collapse or throw up from exhaustion. When that happens, run home.
Don't take crap from anyone. Lineman can get away with anything. If you knit, than knit. Your personal life is no one's business.
Eat. Eat a lot. Lean meats are great and so is chocolate cake. Although you should skip this step if you are an end.
Hang with other lineman. Unless they are a bunch of troublemakers, then stay clear.
Sleep a whole lot.
Work out twice as much during the summer.
If you're on defense, to get through the line look at his fingers. If the knuckles are white, it's probably a run, so pull back and he'll fire through. Just cut to one side and he'll miss you completely. If his knuckles have color, then it's probably a pass so charge low and hard.
On offense, to avoid this, curl your ring finger under.
This is a three point stance. To do this (right hand stance) put your feet square with your shoulders now move your right toes back to your left heel. Now put your right fingers on the ground (not palm, not fist, fingers) now you should be leaning hard into your fingers. Keep your back level and head up. Offense put your hand on your knee. Defense put your left elbow in front of your left knee (at a 90 degrees) hand straight. Defensive ends put your left arm behind you. This hurts your fingers but you'll get used to it.

By the way, remember this. Lowest man wins. This is true in blocking, tackling, getting through the line, all football. Tackling is different for lineman. Here is the best way to do it. Lineman usually aren't in open field to make a tackle so the first step is easy, get close. When you are about one foot from your target sit your butt back, lean slightly over your legs, put your hands in a fist, arms at 90 degrees behind your back. Now jump straight out at him. There is really no time to think so if you can hit your helmet at the ball. BAM. It will knock the ball loose. If not than try to rip the ball out with your hand.