The Deadlift (In my opinion; and many coaches better than I) is probably the single best movement to create human strength. If done properly it can be very safe as well.
Learn the basics first with about a 5'0" stick or piece of PVC pipe.
1. Establish good posture. Use a stick on the spine (as in video) to make three points of contact with the knuckles on the sacrum (butt-crack), the upper back, and the head touching stick.
2. Hip Hinge. This is critical to learn for good lifting mechanics in general. Practice this with Step 1 (above) a few times to establish the sensation of hinging at the hip and NOT articulating in the spine.
3. Once you understand the Hip-Hinge, now begin at the standing position with the bar in front of you at arms length. Begin to hinge at the hip with the bar sliding down the front of the thighs. The hips will travel backward, but keep even distribution of weight on the feet. As you get to the kneecap, move to step 4
4. At this point when the bar starts to crest the kneecap, begin to descend into a squat until the bar reaches the mid to lower shin area (maintaining a flat back throughout). This ultimately is the beginning position of the deadlift movement as things are generally lifted from the floor, however we are just learning the basic movement pattern with low weight.
5. From this position at the lower shin, begin to ascend out of the squat, making sure the knees begin to straighten. Once you are back at the crest of the kneecap, you can simply unhinge the hip back into the standing position.
Note: the spinal position is rock solid and does not change at all throughout the entire movement.
Now you have the basics. GO PRACTICE! And you you have ANY questions, please don't hesitate to reach out to me.