using the post new link
If you want "spell check" functionality and are running Internet Explorer, (IE5, IE6, IE7, IE8) download and install this add-on:
http://www.iespell.com/download.php
First time you run it do it on a little piece of test text, you will get a warning something like "do you want to allow active X ..." Go ahead and allow for all websites. (the test text disappeared when I did it, so don't start on something you spent half an hour typing!)