how do i insert a picture?

you can't paste a picture. if you want to insert a picture from another web page, you've got a few options :

1 - right click on the picture and click "save as" and save it to your hard drive, then click "Browse" where it says Attach File and find the file

2 - right click on the picture and click "Properties". you'll see the Address location of the picture. you can highlight that and then click the IMG button above the reply box and paste that URL you just copied into there.