My take on the Smith Machine for bench is the same as those who criticize it's use for squats. The fixed bar path of the machine doesn't really duplicate what your muscles "should" be doing in an actual bench press. My guess is that the risk of injury is not the same as a machine squat but you won't be getting any stronger. A concern of mine would be is that you'd think you could actually lift X amount of weight, and have a false sense of confidence when it is time to pick up the real olympic bar.

Bench is my weakest lift and I get that there is a learning/strength curve to get it all done right. I do think it's worth trudging through the groundwork rather than moving to the machine. It's not the same.

I love Krista's site for deadlift form instruction: http://www.stumptuous.com/dork-diva-deadlift-and-stiff-legged-deadlift

I also like watching Mark Rippetoe's youtube videos on deadlifts (and any other lifts.) Well, not like, exactly. It's sort of boring, in one way. But I digress. He walks through the whole lift, and shows people doing the lifts, and points out things they need to watch for, and gives them tips. It's like a mini-lesson, as opposed to some that you just google across and it's just a dude lifting super-heavy and wanting to record it for all posterity. No instruction on those, plus you have no idea if the guy's even doing it correctly.