I liked Hoge's "Learn Real English" better, however it's for intermediate to upper-intermediate students.
He can give a look to this site, it's good for explaining grammar, (not the tenses only, he should dig through the site for other things).
Also he can look up a course in English pronunciation, like "Tree or Three" or "Ship or Sheep" or "English Pronunciation in Use" or something like that.
Of course one needs a hell of a lot of practice to achieve tangible results.