I guess water is the most important. Figure out how you would get water without electricity, and if you know a source, make sure you have something to filter that water with, like a Berkey water filter.
@Hubert -
http://www.saveourskills.com/ is a great site, although still young. Gotta learn the skills now. There wouldn't be a web to refer to if the SHTF. I personally see a very bright future for us all, but that doesn't stop me from preparing for a possibly dark one. Remember, being prepared for disasters is smart. I live in earthquake country. I don't prepare for the end of the world (why bother?). I prepare for small or medium disasters, or even just a severe economic downturn.
Oh, yeah, seeds and the knowledge to know what to do with them is pretty paramount.