I got out all my LEGOs from my childhood for the kids to play with several months ago. That got me thinking about the sets that I owned and tried to find the instructions for them. I found a website that had copies of old instructions for old sets. It is great, though not the easiest to search if you aren't entirely sure what you are looking for.
I spent quite a bit of time trying to put together my castle set. The kids helped me sort through the pieces while I put it together.