newb: integration of pre-made rails modules (blog, wiki, others)

Hi,

Sorry if this is a double-post. I tried posting this question last night but I never saw it show up, so here I go again...

I'm new to RoR, and very impressed. I've done a little work in the Java world, and Rails is much more friendly in a don't-have-a-million-xml-files sort of way.

Anyways, I'm thinking of switching to RoR for a website that I'm building. So, my first step is to grab as much pre-made functionality as I can. However, I cannot seem to find how this is done in RoR. Do I use generators? Plugins? Gems? How do I go about finding and integrating pre-made functionality? In Java, I would find the tool (like Hibernate) and get all the necessary JARS, and place them in the correct /lib folder. Is there something similar for RoR?

To give a better idea, here's what I'm looking for:

1. blog
2. wiki
3. login
4. user groups (ie. groups each have a separate space, blog, wiki, etc.)
5. user management (add, remove, disable, ...)
6. user roles (admin, moderator, user, guest, ...)

From what I've seen, these are very common RoR modules, and I know many other websites have this stuff. So, how do I go about finding and re-using what has already been done?

Sorry if this is an obvious question. I truly looked around and found nothing. If there is a URL or document that answers this stuff, please feel free to post it without any explanation. I understand that answering the same questions over and over can get boring.

Thanks,
Micah

The primary way to share bits of functionality is via plugins. You can learn more about the plugin system at http://wiki.rubyonrails.com/rails/pages/Plugins, and find a searchable database of available plugins at http://www.agilewebdevelopment.com/plugins.

And with stuff like blogs and forums, look for Rails Engines (a special type of plugin): http://rails-engines.org/

Jason