I introduce basic things like magnetic letters, Wikki Stix, playdough, and white boards as a whole class activity at the beginning of the year so that all students are able to at least work with these items. Later, in small group reading, I introduce word games. This gives them a chance to practice with a partner with me right there to help out. It worked really well last year. This way you can also model how to properly set-up and put away the games and pieces with just a few kids. Then you know that everyone was taught properly and they have no excuses!
I add new things about once a month to keep the interest high. I model the new activities like a preview for a movie (a coming attraction in the word work area). They get sooo excited with the new possibilities!