In reply to bethechange:
Do you/they want a guide for finding the way around, or for instruction? If the former, a guide really isn't necessary. The guidebooks give a good indication of the areas (although the maps in the purple guide take a bit of getting used to) so just turn up and have a play.
If the latter, Font probably isn't the best place to learn.
If you/they are experienced and are looking for lifts, partners, spotters etc, taking a wander around the Musadiere campsite or the Le Grez one will be a pretty certain way to find groups of boulderers.