If you want to study for TOEFL or IELTS tests, Where will you start studying?
Reading
Writing
Speaking
Listening
Of all the TOEFL manuals I tried, I found Barron's to be the best, because it was the toughest. Their level of difficulty was most similar to the actual test, while other manuals seemed to be too easy. Experiences differ, of course; this is just my 2 cents.
I didn't even have to buy any of those guides, just went to the local library or bookstore and studied it there.