You've got the basics set up:
- A gallery is created in the backend
- For that gallery you've set permissions
- Frontend My Galleries is enabled
The general permissions for Joomla 2.5 are explained here:
http://docs.joomla.org/ACL_Tutorial_for_Joomla_1.6, so reading that might help you with Permissions. RSGallery2 has some extra permissions that work in a similar way.
There are three places where you can set permission for RSGallery2, they are for three "levels".
- Component: Backend > Components > RSGallery2 > Control Panel > toolbarbutton: Options
- Gallery: Backend > Components > RSGallery2 > Gallery > [Edit a gallery] > Click "Set Permissions" (only visible when the user is allowed to change permissions)
- Items: Backend > Components > RSGallery2 > Items > [Edit an item] > Click "Set Permissions" (only visible when the user is allowed to change permissions)
Permissions are inherited: items inherit them from the gallery they belong to, subgalleries inherit them from the gallery they belong to, galleries inherit them from the permissions set in the component level. And if it's about the core Joomla permissions (e.g. Configure permission at component level) it is inherited from the Global settings (Backend > Site > Global Configuration > Permissions).
For example, the vote and comment permissions are RSGallery2 permissions, they can be set on component level and on gallery level (not on Item level).
In the Control Panel there are two Help buttons (Backend > Components > RSGallery2 > Control Panel > Help (the left one)). The left Help button (could not find how to give that one a different name while having this "Help screen" behaviour) offers some RSGallery2 ACL Help.
For example: you want a user to be able to create a gallery in the frontend. Then the user should have "Create" permission" on either the component level or "Create Permission" for a gallery in which this user is allowed to create galleries (however, if on Component level create permission is explicitly denied, you cannot allow it 'down the inheritance tree').
Exactly what you want to achieve, user only allowed to create/edit own galleries/items, is not possible with RSGallery2 3.1.0, however, it will be available in a next version. You can already try that with the latest "Nightly Build". See this post:
http://www.rsgallery2.nl/nightly_builds_rsgallery2_joomla_1.61.72.5/what_will_be_new_next_version_posting_guidelines_download_16673.msg43927.html#msg43927 (a Nightly Build with SVN number higher than 1072 will do). I'd love some feedback on this ;-)
This possibility of using a permission to "Edit own" or "Create own" allows the administrator to set things up that in the frontend My Galleries (not the backend, that's not implemented yet!) users can create galleries in galleries they own and create (upload) items in galleries they own and edit items/galleries they own.
Now, hopefully this info will get you started. If you have any more questions you know where to ask...
(By the way: it's good to mention the complete version number, so not RSGallery2 v3, but v3.1.0 and not Joomla 2.5 but 2.5.4.)