I had also not known anything about them until I found one of their patterns at a flea market. This was one of the very first vintage patterns I ever bought, and it was one of the first items in my Etsy shop to sell - just a fun little mod summer dress:
Some of my favourite ones are:
I have also recently acquired three issues of their bi-annual "Journal des Modes" in which they published their newest patterns - only the more glamourous ones though. Sleep- and homewear it seems was probaly just published in their weekly family magazines. Click on the magazine covers below to view the complete magazines in an online album! They are gorgeous to look at just for the beautiful, colorful illustrations.
To keep track of all the information I have so far, and since I have faithfully been uploading or linking every pattern in my shop, I have also added this to the Vintage Pattern Wikia: http://vintagepatterns.wikia.com/wiki/Category:Ringier
I will keep adding as I find out more - I hope to be getting more of the magazines soon.