The French government has launched a small website called oups.gouv.fr. - “whoops.gov”. I’ve found it quite amusing but it’s also useful for ensuring you’ve covered all your bases when dealing with admin (though alas not for cartes de sejour, it covers such things as moving house, changing job, filing taxes etc). It’s light in tone and easy to read. So, I think, quite a useful little resource.
However, what I’m really looking for is the other side of the coin - an “oh bugger, the French government got it wrong” website. I need that much more regularly.