To finish off this thread for anyone searching through it in future:
The refugio is obvious next to the road just as you enter town. It costs 18euro a night (11 if you are a member of a climbing association with reciprocal rights) or 29 including dinner (it includes breakfast anyway).
Bivving in, or next to, your car in the car park doesn't seem to be a problem, and we saw a tent about 5km back down the road in a random open space.
I dont' know about getting there by train - but it might be a bit of a mission. You don't need a car while you're there (5min approaches) but getting down to the big town for groceries would be interesting without one.
You can buy the (fairly new) guidebook from the refugio - I think it cost 15 euro.
The little shop just up the road sells chalk and guidebooks, but isn't always open (wasn't open during the week, but opened on the weekend when the place got busier - same for the bar).
Huesca is about 35 km away and has a climbing shop (where you can buy replacement chalkbags when your chalk bag string knot comes undone unexplicably half way up a route) and a barrabes discount/clearance store (which is kind of cool if you want some randon cheap stuff - but doesn't have anything that useful really).
We got away fine with a single 60m rope, but doubles might be handy I guess.
And one final thing - regular training on 2 bolt routes at South Central is perfect for 300m of steep jugs... ;)