i have created a website for a non profit organization. People on the site want to post stuff . i want to figure out the best way to allow them to do this.
to clarify, the functionality of wordpress is all i need (people posting content and pictures).
You do not need to install a whole cms solution, though wordpress can host an entire site, not just blogs.
You could hack it by using a hosted weordpress and displaying it in an iframe (this one might get some flames - but it works and it's easy)
You could also install wordpress on your server. By the sounds of it this is not your expertise, and while setting up wordpress is getting easier every release, for smaller sites I would much rather recommend pivotx
wordpress has a lot of overhead and requires a mysql database. The templated, while there are more available than in pivotx are harder to create. So I'm suggesting the other solution because it does the bulk of what wordpress does, and though it has far far far fewer plugins, it is a lot easier to theme, as it uses smarty.
It's easy to integrate Wordpress into a static html site. Integrating WordPress with Your Website « WordPress Codex. (You do need mysql, but almost every hosting company out there offers it.)
If you want to convert an existing html site to Wordpress, look at Theme Development « WordPress Codex. Developing Wordpress themes is no more complex than other CMS's, and here are lots of tutorials out there. You divide up your html into header.php, index.php, page.php, footer.php, etc., and css into style.css. If you do a standard Wordpress theme, then plugins will work fine.
Go ahead and do a full install of Wordpress; there's no option for a minimum install. WP is small, anyway.
If you need a finer degree of working with editors, subscribers and contributors than Wordpress offers out of the box, look at different plugins that offer role managing capability, giving administrators the power to give different levels of permissions to users to write, edit and publish. WordPress › Search for roles « WordPress Plugins
You can pull other content into Wordpress via RSS, too, and either have that content appear as an RSS feed, or have it integrated into published posts. FeedWordPress | simple and flexible Atom/RSS syndication for WordPress
You can get a free account at wordpress.com and try out a limited version of Wordpress, limited in that it is hosted by wordpress.com and you have a small number of plugins and css modifications you can make. But once you selfhost Wordpress, then you can do much more with it in terms of plugins and adapting the css to an existing site.
There are a few popular free Wiki packages out there these days. By far the most popular would be the framework behind Wikipedia - MediaWiki. Wikis' are a proven way to let users create the content, with systems in place to prevent vandalism/spam. MediaWiki also has a whole bunch of great plug-ins for anything you would need.
Another Wiki option is to use the Wordpress-Wiki plug-in for Wordpress. It lets you use Wordpress, but with some features of a Wiki. Not as feature rich as MediaWiki, but a good option if you really like Wordpress.
This problem/scenario is pretty common. And the most common solution is to install a CMS. Our compagny installs Drupal to let end user manage their website easily. They can edit menus, and change content as easily as you write a document in word processor software.
But there is a lot of CMS out there...
Have you tried blogEngine.net?
I have two sites http://www.dotnetscraps.com and http://www.abhyast.com/ that are hosted using blogEngine.net. It is free and has multi user support, and the best part for me is that it supports both XML and SQL hosting. Anything that you post automatically ends up in the App_Data folder which is what you need to backup.
http://www.dotnetblogengine.net/
There are a plenty of themes to choose from, and if you wish you can customize your own theme without much effort.