We used Sonlight and they use the Explode the Code (ETC) workbooks along with word lists and phonics readers, something similar to Hooked on Phonics. They all work together on the same new word families each week. We kept up with the ETC series even after we dropped the reading program. I think it helps with spelling and vocabulary. ds9 will finish ETC 8, the last of that series and we will next use Megawords by the same publisher as ETC for spelling and vocabulary.