Once you have started a weblog you can add things to it.

Below a post or image there is a dropdown with a list of weblogs by you. Simply select the right one from the list and it will appear at the end of the weblog.

To make it appear in the middle of the text you have to add tags - something like {{1}} to insert note/image 1. The '1' is the ordinal of the post/image in the list at the base of the weblog when you are editing it.

It's been a while, so I think that's how it's done ...