(I tried googling the topic, but I'm very lost as to even where I should start. The main question that I'm interested in could be summarized as, "How do we ensure our knowledge as a species/society is not lost in an unintelligible format?")
(I tried googling the topic, but I'm very lost as to even where I should start. The main question that I'm interested in could be summarized as, "How do we ensure our knowledge as a species/society is not lost in an unintelligible format?")
But this is useless to the post-apocalyptic hunter gatherer, civilization would have to be reestablished by then. And hopefully they at least understand the idea of writing words on paper and don't just worship it as a religious thing.
There has actually been work on doing that, attempting to mark radioactive waste dumps in a way even someone in a completely different culture from a distant future could understand. It's really interesting and there is pdf on it here: http://prod.sandia.gov/techlib/access-control.cgi/1992/92138...
If you are going to communicate with a completely alien civilization, that is one that can't even understand images, expressing information is even more difficult. My best guess is that you send a message with a really obvious pattern to it, then use that pattern as a basis for sending more information.
For example, send a ton of examples of simple code in a simple programming language, and their output. They can figure out what it means. Then encode your messages in the programming language somehow. Send a simulation of 3 dimensional space and little objects in it interacting, for example.
Somewhat related: http://lesswrong.com/lw/qk/that_alien_message/
It could possibly be made future-proof by using a flipbook format, assuming we can find a suitably long-lived material to print on.
I kept thinking about the "how to tell future people about radioactivity" example and I think it's hard to convey the actual effects, while it may be easy enough to convey that it's dangerous.
A movie would be much more apt at explaining what was there and what the consequences of irradiation are that a few stills.
Also, there was another page along the lines of what you're thinking: https://en.wikipedia.org/wiki/Wikipedia:Terminal_Event_Manag.... Although it was an April Fool's day joke, it does give some idea of what's involved.
For less advanced future generations, given the lack of a universal language I think the best you can do is store copies in many languages and/or translation dictionaries, and hope that at least one of them survives. http://rosettaproject.org/disk/concept/ is an interesting take on this.