yes, i think that creating a subcategory for modules and plugin translation like in j1.5 is useful and a very intuitive way to find files (there's a good component for this
I created the archive files and added to each one a personalized (or "costumized" if it can be said) README.txt file in which ones i explain simple instructions.
readme files sounds like this:
Unzip the archive file, then copy language files to main plugin/module folder (name of the folder in brackets) on your server.
For plugin with language(s) folder, i just specified:
Unzip the archive file, then copy "it-IT" folder into "language(s)" folder of the plugin/module on your server.
The full path should be something like: ... (complete path)...
All files in attachments, hope it's useful. bye