The information about plug-ins is maintained by the respective authors. Authors can only maintain the information about their own plug-ins, moderators can change any aspect of any plug-in.
Check out the "Create Content" menu and select either "Plugin" or "Script", depending on what you want to add. This will bring up a form for you to enter information. Make sure to submit the form!
Go the the My Content page, select the plug-in you want to change and click the "Edit"-Tab.
To be able to add or change content, you need an account and be logged in. If you don't have an account yet, sign-up using the link on the left. Of you have one, log-in in the same place.
The main way of searching and browsing plug-ins is through their tags, so choosing tags is quite important! Please keep the following two points in mind:
Click the FAQ's and How To link below.