Prior to taking the written test be sure to read the Wisconsin Motorist Handbook. Or as an E book HERE . There are 19 questions in the back of the book and those will be very similar to at least 19 of the questions found on the test.
Also, the DMV offers a free smart phone app in the iTunes Store or Google Play for practicing the written test.
The Written Test is divided into 2 parts. A 50 question "General Knowledge" test and a 15 question "Highway Road Sign" test. The test is very basic and most students will have no trouble passing the test on the first attempt.
NOTE: In either case above, make sure that before the student goes to the DMV to get their instruction permit that they have a signed MV3001 with either the scores lined out (if they did not take the test with us) or with the test scores entered (if they took the test with us) and that the date the instructor signed the form is NOT more than 60 days old.