The Virtual Polyhedra website is a virtual encyclopedia of polyhedra constructed and maintained by George W. Hart. The site claims to have over 1000 examples of polyhedra, which may be viewed and manipulated in 3D as virtual reality files by using a free VRML browser (an explanation of how to do this is included at this website, and these browsers are available for nearly all types of computers).
This site is a self-contained tutorial, reference work, and object library for those interested in polyhedra. An added feature is a "how to" section on building paper models of polyhedra in the classroom, as well as pictures of actual examples built by the author with materials such as paper clips, soda straws, marshmallows and toothpicks, and plastic construction sets, among others.
The Pavilion of Polyhedreality section is a collection of art works and art projects by the author. These works are virtually constructed virtual polyhedra (what else?), such as a rhombic triacontahedron built from apples, oranges, and forks.
This resource can be used to start planning for a focus on geometry, including platonic solids and polyhedra. The Classroom Ideas section contains polyhedra-related construction activites, which can be used for class projects. Your students can create a variety of paper, wood, or other models of polyhedra. They also can play with the virtual polyhedras contained on the site, which allow students to travel inside them to gain a perspective not possible in paper models.
In addition to these models, there is plenty of related mathematical background material at various levels of depth that you can use with your students to help them understand the concepts.