I'm trying to write a slideshow for joomla. Specifically one that will be placed next to an article (no necessarily associated with the article though). Should i write a component, or a module? OR should I write a component that is placed in the page using a module (like the com_banner and mod_banner stuff in the joomla basic installation).
I know I am reinventing the wheel, but I really want to learn about joomla modding.
If you want to associate the slideshow to a specific article i think you should write a component, because in this way you have more control on the article and you can manage its structure and its layout.
You want a module. You can assign modules to any menu items.
Modules will appear on that page and "sub-pages". For example, if you assign a module to a menu item that points to a "Article blog layout", then it will appear on that page and the articles linked from it.
If you only want one specific article, or any page without a specific menu item, create a new menu called "hidden menu" and make a menu item in it. Menus don't appear unless you publish the menu module.
By the way, there are many slideshow components for Joomla already out there - Photoslide from gavick.com is pretty good, and free.