Yeah, deadlifts get a bad rap from some people. My chiropractor told me not to do deadlifts when I was about your age, and it took me a long time to realize that he was an idiot (not all chiros, just him). Having said that, my back has never felt better than it does now, with all the squats and deadlifts.
There are tons of good articles here on T-Nation about the deadlift. Check them out. The “Mastering the Deadlift” articles are very good; maybe not written with a complete neophyte in mind, but worth a read, with some good tips.
It is possible to over think any exercise. A deadlift is one of those. The important thing to remember is to never ever bend your lumbar spine when it is under a load. If you do flex your spine, it is likely that you will discover why some people consider it bad for the back. If you can figure out how to keep a “neutral spine”, the deadlift is fairly simple to figure out.
With your feet about shoulder width apart, grip the bar with your palms facing you (overhand grip). They should be wide enough apart so that your thumbs clear you legs when you lift the bar, but not much wider than that. The bar should be right over the middle of your foot. Your shoulder blades should be slightly forward of the bar.
Take a big gulp of air in your lungs and hold it in. Then lift the bar. Keep back on your heels. Remember, you are not initiating the lift with your lower back. The only thing the lower back does is stays straight. The bar should stay very close to your shins.
Your knee angle will open up fastest at first, till the bar clears them, so that you’ll be sticking your butt back. Then your hip angle will open completely as your knees complete extending, finishing the movement. Then you put the bar down in reverse.
Start very light. Don’t think you’re such a badass that you can go in and start deadlifting 200 pounds. Regardless of whether you CAN or not, you SHOULDN’T until you feel comfortable with your form.
Deadlifts are probably the most exhausting exercise I have encountered. They’re very hard. And they will make you feel powerful. There is nothing that will substitute for them in terms of making you mentally tough and physically powerful. You won’t be sorry if you do them.