Should have asked me - you have my number/email/etc... I'd have told you straight away that you can get manuals from http://public.servicebox.peugeot.com
(free registration req'd). PSA cars are all very very much alike - I can probably list 10 parts off the top of my head that the 406, 206 and the last-gen Citroen C5 share ;)
You've got a post-2001 206 haven't you? That'll mean that it's cursed with multiplexed wiring and a dreaded BSI instead of plain old switches and relays. I'll take massive looms you can troubleshoot with a couple of lengths of wire and a spare bulb over that EC-required crap any day.
Presuming whan you say "a/c has packed in" you mean JUST the aircon NOT the heater/fan (otherwise I'd see if it's possible on the 206 to pull the blower fan from under the passenger footwell and test that - a known pug weak point), here's what I'd do for initial troubleshooting:
1) With the engine running (the compressor is driven by the aux belt) and the bonnet open, slowly switch the a/c on and off, or get Caroline to do that while you shove your head under the bonnet. You should hear a noise slightly after activating it as the clutch solenoid engages. This should also be accompanied shortly after by a change in engine tone as the extra load causes the revs to drop momentarily before the ECU adjusts by opening the idle control valve more.
If all you hear is a click then it's probably the compressor clutch solenoid. About £350 from a dealer, but just get a used compressor from a breaker and take the opportunity to renew the aux belt.
If you don't even hear a click, try sticking a bulb or multimeter across the 2-pin wire coming from between the compressor pulley and the compressor unit. There should be 12v over there when the a/c is on.
2) If that all works, take it to an a/c specialist and ask them to check the pressure. Chances are you've got a leak somewhere. DO NOT trust someone like Kwik-Fit to re-gas your system whatever you do.
3) If the first step results in nothing, you could be in need of a new BSI. Check EVERYTHING electrical on the car outside the engine bay. Anything else wrong/intermittent and it could well be time to kiss your wallet contents goodbye.
4) Nothing else wrong? Yank out the control panel (very carefully if it's not a digital panel!) and plug/unplug the connector(s) a few times. Should be a pair of torx screws holding it in at the bottom, but you'll have to pull out the fascia panel to get at them. From servicebox, looks like you need to unclip and remove the clock surround, remove a couple of torx screws from the top, then unclip the main fascia. Go by the haynes, not me for that one ;) Shouldn't be difficult though.
5) All else fails, it may be worth finding an indy garage specialising in french cars, or a decent automotive electrician. Don't waste your time at a pug dealer though... They'll typically charge £50 for a read of the fault codes (unlikely to be anything stored there) and then they'll randomly fit parts, charging you full whack plus £100+vat/hr labour. Yes I do mean randomly. Most pug dealers will try to fix a problem like this through trial and error, with you being charged every step of the way. I read the stories of so many ripped off people on the 406 owners club forum, often making their first post out of desperation only to be replied to 5 mins later with the exact fix including part number
A few quid for petrol and I could have a look at it the weekend if the weather's suitable for a nice brisk Peak District drive sideways... Not guaranteeing anything though ;)