Need advice on using a blog for class

As I go through the semester, I have all of these great ideas on how to improve my course for NEXT semester.  However, it's still possible I could try a few of these things this semester if I act quickly.  I'm throwing this out there in case any of you have ideas or experience with this sort of thing.
I'd like to use a wiki or a blog for my climate change course.  The wiki or blog would serve a few purposes.

1. A place to link to readings and have a place for students to comment on the readings.
2. A place to post summaries of class lectures/discussions
3. A blog roll of climate change blogs
4. A twitter feed of a few good climate change tweeters
5. A place for student generated content.  

Let me expand on #5.  I have 30 students and they each were assigned a country, which belongs in a group with three other countries.  For example, the European Union, East Africa, the Middle East, Coastal South Asia, Large Asian Countries, Developed Countries, West Africa, and Latin America.  Each group then has four countries under its heading.  Each student is responsible for writing four papers throughout the semester on their country and then joining with their sub-group to decide on main talking points they can bring to the table for class discussions.  First, before we can get to discussions, they were assigned to write a paper and give a two minute presentation (2 slides) on the climate of the country and how it shapes that country's culture and society. 

I also want students to get a feel for other students' regions, not just their own, so I need a place where they can check out the other regions beyond our two minutes in class for each country and be able to add their comments or suggestions for peer review.


After the climate and culture assignment, they have upcoming assignments on climate change contribution, climate change impacts, and climate change mitigation and adaptation for their respective countries.  These assignments will culminate in a sort of in class United Nations discussion/debate on policy.

Okay, now you know what I want.  I imagine this colorful space where students can create their own page for their country, covering the four parts of the project.  I imagine a space where I am the center of control and can have the latest reading or announcement for them as the first thing they see, but the pictures for the countries in there peripheral view that they can click on.  (I also want those countries organized in their groups.)  I think having this be public would be fun, but not required. 

I have experience with pbworks wikis, blogging, and most commonly I just write my own html for course webpages.  I need a space where introductory level students can add material without having to code.  I want it to be pretty, welcoming, easy to navigate, students spending lots of time there because they keep finding more information to check out and comments to make.  Any thoughts?  Can I have that much control on a blog?  or does the newest post HAVE to appear on top?  A wiki is not as pretty as a blog and I think they are not as intuitive to use.  I'm about to dive into a bunch of peer reviewed literature on the topic and am hoping to find some ideas and current class blogs or wikis, but any help you have now will save me time!  If you were my student, would this whole idea of public publishing of class work freak you out?  Would it make you try harder?  I tried experimenting with this blog on how much control I have over content placement on the main page... I have no control.  Help!  What platform would be ideal?