I have used Explode the Code with great success for the last 9 years. It's an excellent series of workbooks. It really helps kids learn their phonics skills and improve their reading and spelling abilities.
My kids are learning soooo much. My son is 6 and on book 2 1/2 and he is doing great with reading and spelling. He is really excelling with a mix of these books and phonics pathways. :0) My second son is 4 and just finishing the last get ready for the code book. I will get him the first explode the code very soon. We really love how these books work. I tell everyone how much we love these books.
We absolutely love this series. Homeschooling family: kids ages 6, 6, and 8. All are at a different place in the series, but they can all pull out their workbooks at the same time and do great self-led learning! They enjoy the cute pictures (drawn by child artists), love the silly sentences they "get to read" (note: not "have to read") - and there is immediate success and feedback because the units are short enough to hold their interest. We have tried Astronauts to Zippers, Ordinary Parent's Guide to Teaching Reading by Bauer, and also Saxon Phonics/Spelling - Explode the Code is head and shoulders above the others, as far as its abilities to retain their interest and keep them motivated to learn. I am very satisfied with how their reading has progressed since beginning these workbooks about 5-6 months ago!
The variety of activities in each lesson work well for my second grader who struggles with spelling, reading and writing. He actually seems to enjoy doing the lessons! We have not been using this workbook for very long but I believe with continued use we will see improvement in our child's spelling abilities.
Simple black and white illustrations, non-cluttered page layouts without too many problems per page, incremental information, lots of review...exactly what one of my kiddos needs. I also appreciate the various exercises that go over the same information in various ways. A page a day, or even two pages when especially motivated, have been a great add-on to our other reading exercises.