This site appears to still be under construction, but there are many useful tips on teaching grammar and using the correct punctuations, and sentence structure. It is also very easy for a student to digest.
About the site: "This site is brought to you by Loyola Press, publisher of Voyages in English: Grammar and Writing. First written over sixty years ago, Voyages in English is a focused, rigorous grammar and writing program for grades 1 to 8 developed by the Sisters, Servants of the Immaculate Heart of Mary, Immaculata, Pennsylvania. Newly revised for 2011, the program features robust grammar instruction and practice, along with lessons and workshops in a variety of writing genres."
~posted by Andrea from Notes from a Homeschooling Mom