Website Review: englishonline.net
In short: For $39-$129, you can access lot of good writing advice and have a teacher look at your stuff. You’ll definitely improve.
This site is half pay stuff, half free stuff. You can pay for writing courses. They look like they’re best for really advanced students, so some students might like a book that’s a little simpler. Still, the content seems strong. The Business Writing course looked especially good. You can also take these courses: “Essentials of Writing”, “Technical Writing”, “Research Essay Writing”, and “Resume Lab”. (The “Essentials of Writing” course would be best for lower level students.)
For free, you can listen to cool conversations with nice supporting materials. You can also check out daily vocabulary, idioms, and grammar points for free.
For students: Once you sign up for a writing course, you can access forums. If lots of people put stuff there, they’ll be great.
For teachers: Why not recommend this site to your students? Paying for a course, could be just the motivation they need to take their skills to the next level.