You can find required permissions in the Administrator Permissions section.

1. Just execute /lands edit <land> to select the land you want to edit.
2. Then execute the command you wish to execute for that land, just as normal.

Actually that's all. The edit command allows you to edit every aspect of all lands. Also, the /lands admin command allows some admin only actions, such as opening the menu of a player or land. The command autocompletion and in game help pages, make it self-explanatory. You may need some permissions to do certain actions for other lands. You can view them here.