To insert your profile pictures for your individual entry page just make a new weblog entry or click "EDIT IT" on any entry you already posted. Then click Choose under Extras in your Weblog Editor window.  A pop up should appear with all the profile pics you uploaded - just click on the one you want to show up, and that's it.

Please note that the pic you choose in Weblog Editor appears on the *individual entry page* for that entry (if you have comments enabled, it's the page where people can leave comments.)