I would personally recommend "The Complete Guide to the TOEFL -- iBT edition" by Bruce Rogers. If you follow the link on the bottom of this message to my website and go to the "What you need to take lessons..." page, you will find links and more information by scrolling down to #4 (such as the ISBN #). I think it's a great book overall, but especially when it comes to integrated writing and speaking; you need to be careful with many other TOEFL texts since most (believe it or not) don't actually replicate the integrated writing task correctly.
By the way, you seem to have an excellent command of grammar and vocabulary, but the word you are looking for is "advise" (VERB) rather than "advice" (noun).
Best of luck to you.