We have scoured the Internet to find sources to help you identify marks on ceramics.
Kovels.com offers a pottery marks database, currently for $3.25 per month.
Chinese pottery marks are a study in themselves as many marks are repeated in later dynasties.
Gotheberg.com has some nice background information in addition to listings of dynasties and marks
Below are some PDF files you can save to your computer and use when you need them. Just select the link. When the file opens, you can save it to your computer.
Handbook of Marks on Pottery and Porcelain, 1914: Handbook_of_marks_on_pottery_porcelain
Marks of American Potters, 1904: Marks_of_American_Potters