My 2-year old MacBook Pro's hard drive started making a really scary sound a couple of days ago anytime I try to put it to sleep (and sometimes just locks up). Bad news! But, hey, it's 2 years old, and I'm getting a new one in literally a week (and my wife is eying my current one with a scary look in her eyes).
So, I bought a replacement hard drive for it and installed it today. Turns out, it's pretty complicated (and verboten by Apple; you void your warranty if you crack your computer open). Along the way, I found this great site: iFixIt. This site walks you through each step for common upgrades, with pictures. I could have figured it out, but this site made it much easier (and let me know that I needed a Torx 6 tool before I started). A lifesaver.