One of the recurring themes with using OpenGuides is that it doesn't do a particularly good or consistent job of allowing people to use charsets other than iso-8859-1. I've made a page on the wiki:
http://openguides.org/dev/?node=Character%20Sets
which hopefully sets out what problems there are and how to solve them.
Please hack on that wiki page with additions and corrections, and/or make comments on list. Once we have a clear plan of how to proceed we'll need someone to implement it, too :) If you are regularly dealing with non iso-8859-1 charsets at the moment, then your input is especially valuable here.
Cheers,
Dominic.