Man, proper form sure can be confusing. Especially for the squat.
Today, I guy came up to me after I was finishing a set of 135 lbs. x 5 repetitions. He told me I had bad form and was going to hurt my back. He gave me some good advice saying that I was almost going on my tip toes when coming back up, but then he told me that I need to try keeping my back straight and mostly vertical and looking straight ahead. That's contrary to what I've been reading in Starting Strength and in a lot of other places on the Internet.
It is true that I feel it in my lower back after a round of squats. Should that not be happening? Anyway, I decided to drop the weight again and focus on going deep, keeping my feet flat on the ground the whole way and driving up with my hips (my ass). Despite dropping the weight 30 lbs. I really felt it in my glutes and hamstring muscles, so I think I'm on the right track.
Oh, and I got my deadlift up to 155 lbs! I'm finally lifting my own body weight. I struggled a bit, though, and probably sacrificed my form quite a bit, so I think I'm going to drop the weight next time around, though.