Skype is an awesome tool that you can use with your students to bring the world right into your classroom. Skype is easy to sign up for, easy to use, and it's FREE! Here are some resources to get you going on how you can use Skype in your classroom...
Using Skype in the Classroom - Cool Cat Teacher Blog gives you instructions on how to get started with Skype in your classroom.
The Complete Educator's Guide to Using Skype Effectively - The Edublogger has a great document that has everything you need from creating your account to setting up your equipment.
Projects on Skype in the Classroom - this is a great site created by Skype. You can filter your search of projects by age, language, and subject.
Skype an Author Network - find an author who will Skype with your class for a small fee or even for FREE.