Point me in the direction of developing new forum features?
In order to create a forum in drupal, you can start with the forum module. It is a core module, so it will already be installed. The following steps can make forum development simpler:


Enable the module- 

Go ahead and navigate to Site Building>>Modules and check the box next to forums to enable the module.

Set up containers- 

you need to navigate to administer >> forums to start setting up your new forum

Set up forums- 

Each container "contains" several forums. In other words, your
containers are children of the root node and your forums are children of
your containers

Customize your forum for adding content or ideas- 

The following modules can be used for content entry:

BUEditor or wysiwyg
Live
Quote
Smileys
Signatures for Forums
Comment Upload


In order to add the voting/rating features, use the following:

VotingAPI
Rate



Advanced Forum may also be used if you wish to enhance Drupal's core forum module features.