Navigate to the American Welding Society website.
Click "Certification" and select "CWI" from the drop down menu.
Scroll to the bottom of the screen and find seminars located in your area. There are 5 and a half days of seminars offered to prepare you for the exam.
Obtain books such as Welding Inspection Technology; the Welding Inspection Technology Workbook; AWS A3.0, Standard Welding Terms and Definitions; AWS A2.4, Standard Symbols for Welding, Brazing and Nondestructive Examination; and AWS QC1:2007, Standard for AWS Certification of Welding Inspectors, all of which are available for free from seminars, and study them until the exam.