Grammaropolis is a site with some great free grammer tools for teachers.
The site includes a video section that has a video titled "A Pronoun Takes the Place of a Noun" and one titled "An Adverb Modifies an Adjective" which are both very cute. It also includes a book section (with more books coming soon) as well as a grammar song section.
It also has a few fun online games and Word Sort is my favorite.
It is a great game to use for a whole class grammar game. Words fall from the sky and students must sort them into the correct category as quickly as possible. The categories get more difficult and varied as the level increases. Level 1 sorts by nouns, adjectives, and linking verbs, Level 2 with action verb, adverbs, and conjunctions, and Level 3 sorts by preposition, pronoun, noun and interjection. This game would be great to use on your SmartBoard as a whole class activity and also as an individual center station.