Hi Lou Ann - welcome to DC!
Wagner is now American Culinary
- here is a link to their website
. You can contact them to see if there is a Wagner Ware specific cookbook - but I've never seen one. They might be able to supply you with the instructions that come with their cookware (they are not listed on their website so you will have to click on the "Contact Us" button and send them an e-mail.)
Wagner made some great cast iron - and they also made some great heavy-duty cast aluminum cookware (aka: MagWare or Magnalite).
The aluminum cookware is just really great highly conductive cookware that isn't plagued with hot-spots. Like with any other highly conductive cokware - you can usually use a lower temp than poor or slower conductive materials.
One thing about Wagner "Mag" cookware is they have a good tight fitting lid - if you turn the heat off and allow the pan to cool a little with the lid on it will create a vacuum ... if you remove the lid and set it askew a little before turning the stove off (or when you remove it from the oven) it will not create a vacuum.