How to find your Schwinn Bicycle serial number, year, and model
Mark Smith's serial number / year guide:
http://www.bunchobikes.com/serialnumber.htm
After finding the year, compare the bike to the pics in these catalogs and brochures:
1893 - 1940
1941 - 1950
1951 - 1959
1960 - 1970 Miscelleaneous pics
Other Publications
The Amlie - Hufford Collection
1960 - 1979
The Cooper - Findley Collection
1980 - 1990
1991 - 2000
BMX Catalogs, 1980 - up
If the catalog pics are hard to read, roll the cursor around the lower right corner until a square with an arrow at each corner appears:

Click on the square, and the pic will display in its original size.