Storing point and polyline data to file

I'm trying to store point and polyline data to a file so I can save a
session. I'm making a map for a hypothetical transit system. I don't
know much about html or javascript, but I pick stuff up from other maps
I see. Any hints on how to do it, or examples of this executed already?
Thanks for what ever you got.
www.princeton.edu/~alinsky