The Help file for My Calendar says the following, but I do not see them as available when I place them in "my-calendar-custom".
I'm assuming that you're going to upload your own icons -- all you need to do is upload them to the plugin's icons folder, and they'll be available for immediate use, or place them in a folder at "my-calendar-custom" to avoid having them overwritten by upgrades. Your icons folder is: /home/liberati/public_html/blog/wp-content/plugins/my-calendar/icons/ You can alternately place icons in: /home/liberati/public_html/blog/wp-content/plugins/my-calendar-custom/