Grammar : review the grammar reference at the end of the book and do the exercise at the Headway.com
Conversations/Tapes : review the conversations parts at the end of the book.
Reading comprehension of passages: Review the reading part at every unit.
Vocabulary and everyday English: review the words list at the end of the book and do the exercise at the Headway.com
Finally do the tests at headway.com
by the way I did well at the test alhamdolillah :)