I'm finding it's helpful to, at the beginning of your study period, attend the code endorsement seminar offered at the Hobart Institute.
This seminar is followed by an exam, but you don't have to take it then, or pay for it.
This at least shows how to navigate and make sense of the specific code you're planning to test with.
You probably have the fundamentals down, but study the basics of the weld processes you're not familiar with, same with NDE.
Learn to properly use inspection tools, and that each individual code and specification has its differences. No one can remember them all, but still everyone is guilty of mixing them up.
"Never quote from a code book that is not in you hand." is good advice.
Purchase the WIT books listed in the "Body of knowledge" portion of the CWI seminar/exam application.
Use every practice exam you can find.

There's lots of good advice in the forum search history.

Tim

I think for those motivated towards self study that you cannot go wrong with the AWS Welding Handbook Volume 1 9th edition, The AWS Certification Manual for Welding Inspectors (for the questions), and whatever code book you have worked with the most or anticipating working with.

The body of knowledge listed for the CWI exam is almost completly covered in the AWS Welding Handbook. Get any welding book you can find and read it.

There is also a company that has some online training that is pretty good. The company is SonSet consultants.http://www.weld-procedure.com/freecwipartbhelp.html

Thats not to say there isnt any value in a class however things learned over a week or two are different than those studied over a period of time. There are, I am sure, some great classes.

Richard,

First off, don't take this wrong, but your code book is way too old.  Throw it away and beg, borrow, or steal (well, let's not go that far if you want to maintain the honesty and integrity required of a CWI)  or buy a newer version.  You will be testing to the 2010 and it is very different from the version you have.  You can learn your way around it in basic principles but there is much you need to read and get used to in the new book so you can have that older version out of your mind.  It WILL mess you up.

Second, down load the free Part B book of specs and get used to it for the Part B portion because it is different from D1.1 for good reason.  See the other thread here on Part B.

Then, definitely get WIT and study.  Get the other books that go with it, WIT Workbook and WIT Sample Questions-CWI Fundamentals.  WIT-T:2008, WIT-W, and WIT-E:2008 are the order codes. 

While I agree that the Welding Inspection Handbook is a great resource and one that is not handed out at the seminar, WI:2015, as well as the Certification Manual for Welding Inspectors, CM:2008, there is no replacement for the materials and information from the WIT book and the two companions.  They are loaded with practice questions to get you used to what will be required on the General Knowledge, Part A, portion of the exam. 

I don't care how long you have been in the welding field, there is a lot more on this exam than the average person has picked up at work.  It covers brazing, metallurgy, GMAW, FCAW, SMAW, GTAW, EB, LB, SAW, PAW, all the cutting processes, carbon equivalency, inspections, safety, welding symbols, NDT, AND SO MUCH MORE. 

Make sure you go to the newest Publications book or on the website to order, some of my numbers may be old versions.  They have updated in the past few years.

He Is In Control, Have a Great Day,  Brent