If you use the attachment tool that looks like a paperclip above the editing window, it will give you the option of uploading a single image (at a time) or several image URL's at the same time. You can do this for up to 10 images in a single post I think.
Once you have uploaded the images and close the upload dialogue, if you click on the little down pointer next to the paperclip, it will show you the list of images you have uploaded.
You can select any of those images to place in your text wherever you like. The editor will show the attachment tag when you do that. Any that you do not select for placement will be put in a box at the bottom of your post with the label "attachments."
The manage attachments button below the edit window near the bottom of the page, behaves similarly for uploads, but does not do the insert list display.