The following links are various tools available FREE to educators, students, and parents. I've given a brief description of each to help get you started. Some are explanations, tutorials, or brief videos.
Blogging
Here's a video of what a Blog is in Plain English...

http://www.commoncraft.com/blogs 

The following link has some answers to questions you may have about blogging, including grading (sample rubrics).

http://theedublogger.com/2010/07/06/what-you-wanted-to-know-about-student-blogging/

 
Wikispaces.com
Wikispaces is a free site for users to create their own wikis for students, parents, and colleagues to use. This short tutorial gives you insight on how to get started with your Wiki.

 http://www.wikispaces.com/site/tour

Personalize your Wiki. Here you may change the color, theme, as well as add a logo to your site. http://www.wikispaces.com/site/tour/myspace
Add Images and Files to your Wiki. Your wiki will store these files for you.

http://www.wikispaces.com/site/tour/files 

Edmodo.com

Edmodo is an online classroom communications blogging tool for teachers and students to share Files, Links, Polls, and Assignments.

After following the link, click on the Yellow School Bus to take a "tour" of Edmodo. It will give you a brief description of all the tools involved in Edmodo.  

http://www.edmodo.com/ 

This guide will show you step by step how to use different tools in Edmodo to create Assignments, do Grading and post messages, just to name a few. There is a calendar feature as well. 

http://www.edmodo.com/guide/ 

 
Edublogs.org  

Edublog is a free, secure online blog for educators as well as students. The following link has screenshots and some tutorials as well to help you get started with your blog.

http://help.edublogs.org/getting-started-with-edublogs/
Top ten reasons to use Edublog in teaching http://edublogs.org/10-ways-to-use-your-edublog-to-teach/