You can also sign up for the free or paid version of Scripps' Word Club:
http://spellingbee.com/word-club
which gives access to spelling lists as well.

Merriam-Webster's partner site with Scripps, with study lists grouped by language of origin:
http://www.myspellit.com/

Word and spelling games on Merriam-Webster's WordCentral:
http://www.wordcentral.com/home.html

...pronounced like the long vowel and first letter of the alphabet...