Spelling Power 3rd Edition Author:Beverly L. Adams-Gordon 15 Minutes a day and this book are all you need to teach ages 8 to adult comprehensive spelling skills!
Complete with lists of the 5,000 most frequently used words organized by phonetic principles and spelling rules.
Excellent program and cost efficient. Use from age 8-high school for all your children. Comprhensible and fun for the student. Teaches not just memorization, but the rule behind the spelling and therefore the reason. My children enjoy this program and it's flexibility.