In order to share your calendar with other users, you have to set your folder permissions. A manual to do so can be found in the following steps.
You can now change the folder permissions and object permissions by clicking on the blue text.
You have 3 options:
For the object permissions different settings can be set:
Here you have the choice between "none", "own objects" or "all objects".
The administrative right can not be given out, only the owner make administrative changes.