Go to member tools. You will find it at the very bottom of the left menu :)
Then click on Manage Your Storage Space :)
Pics go in to Albums.
Pic's you post from your computer are also in My pictures :)
Documents are where you can store a document file :)
My Attachments are where you find pictures that you attached to a post :)
Clicking on my pictures will bring up what you have stored in your albums :)
Clicking on documents brings up what you uploaded to the documents folders
Click on the PICTURES tab to delete from albums and post
Click on the ATTACHMENTS tab to delete from posts.
Click on the WEB DOCUMENTS tab to delete documents.