Oh hi, I didn't notice your location - welcome.
Is your windshield all scratched up or covered in spots or something? I haven't done a lot of glass polishing, but I suppose if it's never been done before on a car with older windows it couldn't hurt. I wouldn't try applying this stuff in attempt to "wax" the glass though, since that's not what it's for.
Mopac, Overseas Auto, and some dealerships (European cars, maybe some Chrysler dealers) carry Autoglym.
Either Zaino or S100 are good choices. You just have to decide what kind of waxing process you want to go with and pick one. If you have any questions or things you'd like to know about, don't forget to try the Search function first - it's the best way to learn things and often you get more info than any one or few people can give.

Also, you may want to try out the Autopia eBook.
For example, search turned up this very easily:
S100 in Vancouver...
This one isn't as easily found though:
Possible Zaino source for Vancouverites...
HTH