Just as there are many different genres of games, there are many different ways to use games in a classroom.  Most games can be integrated as supplemental material to reinforce recently learned skills or as a review after studying a particular unit.  A few can serve as the centerpiece of a lesson  and some let students explore a subject or career.  Games that offer solitary play options can often be used by students at home or in study hall for skill practice. 

If you are just getting started using games to teach, you might want to look at the following websites.  They outline what game-based learning is, why you might want to use games, how to use games, and offer examples of how they have been used.

Best Practices for Using Games & Simulations in the Classroom:  Guideline for K-12 Educators

This white paper from January 2009 addresses the practical challenges teachers face when they use video games to teach.  It is organized into three main parts:  Selling the Idea, Preparation, and Implementation.  It is very thorough and an excellent resource.

Lure of the Labyrinth Educator Resources and Library

When MIT's Education Arcade creates a game they also include a whole host of educator resources.  If you watch the short videos, you can find out how educators from two very different classrooms implemented the same game.  There is a lot of information and the material can easily apply to other games.

Starting Point - Teaching Entry Level Geoscience

Although this website was created to explore "the ability of on-line resources to catalyze improvements in undergraduate teaching," their pages on game-based learning are excellent and the information can be applied for other ages and subjects.  Follow the links on the left-hand side of the webpage. It was funded by the National Science Foundation.

FutureLab Teaching With Games

FutureLab, the British Organization dedicated to innovation in education, conducted an extensive study on Games and Learning.  You can follow the links on the website to the final report but be sure not to miss Teaching with Games: Guidance for educators.  This report looks at using commercial games in the classroom but the steps they guide you through apply to all games:

Why Use Games?

Selecting a Game

Lesson Planning

Time Considerations in the Classroom

Ensuring Learning and Assessment

Technical Considerations

School-Wide Considerations