Hello,

While strategies are important to ace the TOEFL test, picking up or having an idea of  which book to use for preparing the test plays an crucial role.

So here are the few guide books that you can refer while preparing for TOEFL:

1.TOEFL Test Prep Planner

2.Official TOEFL iBT Tests Volume 1 and 2

3.Kaplan TOEFL iBT Premier

4.Speaking and Writing strategies for the TOEFL iBT

So When it comes to IELTS exam, Here are the few use that you can use while Preparing for this exam:

1.Complete IELTS  from Cambridge

2.Barron's IELTS Super  pack

3.Target Band 7:IELTS Academic Module

4. Collins English for IELTS

5. Road To IELTS: British Council

hope this information may help you,

All The Best .