TOEFL

Yes, there a book, TOEFL Grammar Guide Advanced by Timothy Dickeson that is very good for TOEFL english grammar. It is short, simple, and focuses only on grammar that comes in the TOEFL test.

Yes. If you are already familiar with the TOEFL but want to improve speaking and writing, then the book Speaking and Writing Strategies for the TOEFL iBT is very helpful.

A lot of students prefer Kaplan TOEFL iBT Prep Plus because it's easy to follow and covers everything. The book has 4 full-length tests and helpful video lessons. You can even study on your phone. 

The best book for TOEFL beginners is The Official Guide to the TOEFL iBT (the latest version).

• It is made by ETS, the people who make the real TOEFL test
• Explains every section step-by-step
• Gives you 3 full tests
• Good if you are just starting and want to know how TOEFL works

Usually, the Official Guide by ETS and Kaplan TOEFL Prep have the best reviews online. Students like them because they are clear, updated, and close to the real test. 

If your English is already good and you want a high score. Try Delta's Key to the TOEFL iBT: This is more advanced and detailed. The Collins TOEFL books are also good for improving speaking, listening, etc.

Barron's Essential Words for the TOEFL (7th edition) is good for TOEFL vocabulary. It is made only for TOEFL vocab.

One can check the TOEFL prepration books, which is best for practice: 

• Barron's TOEFL iBT has around 7 full tests
• Kaplan and the Official Guide have around 4 practice tests each

The best book for real TOEFL questions is the Official Guide by ETS, because ETS makes the real exam.

Yes, TOEFL iBT is accepted worldwide for bachelor's, master's, MBA, and PhD programs. Just make sure the test is taken at an approved center.