Can anyone tell me where I can find info about painting styles?

For information on artists living or dead, try sites like: "absolutearts.com" or "worldwidearts.com" and type in whatever you have--artist name, type of work, style of work, medium used, size, etc. Is it a print, a painting, a photograph, an original, a print? These things all effect the value, as does the condition. Also type their name in quotes on a search engine like www.dogpile.com "John Doe", and see what comes up.

If the artist is dead, a gallery link might pop up. A gallery dealing with the works or the estate of an artist can give you a lot of useful information, might be able to tell you the value and if there is a market for the work.