Part of the Reading A-Z family which includes quite a few resources now for literacy skills, Raz-Kids is my favorite. It does require a subscription and they occasionally offer special pricing deals where you can get access to the different websites in a bundle. What I like about Raz-Kids is that it is on-line and another way to get those reluctant readers to practice! Rather than another print-and-teach website, Raz-Kids is for K-5 kids and provides interactive e-books.
While this website is most applicable for K-5 students it would also be useful for special ed teachers or to support students who have not quite developed fluent reading skills. The Florida Center for Reading Research is a multi-disciplinary research center at Florida State University. Over 3 years a team of teachers created a Student Center Activities for use in the classroom. Completely free and downloadable, they are concrete, student friendly and actionable.
This is the second most amazing reading resource that I have found. Completely free, it provides K-12 reading comprehension passages on a wide range of subjects. It provides a lesson plan, downloadable resources, question sets, etc. I love the description about the question sets. The questions for the passages are designed to take students from explicit questioning to inferential.
The Core Reading Source book goes along with Assessing Reading Using Multiple Measures. It is the most comprehensive, systematic and easy to use backbone for developing successful reading instruction that I have ever come across. It is research based and each section provides a theoretical background to the skill and then breaks down both what to teach to students and how to do it. It has language that you can use when teaching students explicit phonics strategies that I have found to be seamles
Amazon.com: Words Their Way: Word Study for Phonics, Vocabulary, and Spelling Instruction (6th Edition) (Words Their Way Series) (9780133996333): Donald R. Bear, Marcia A. Invernizzi, Shane Templeton, Francine A. Johnston: Books
In my development as a teacher, the instruction that I received on how to explicitly teach phonemic awareness and phonics to struggling students was essential. I was lucky to provided this instruction by my district in a comprehensive training on the Core Reading Sourcebook. I have provided a link to the PBS.org course because it is something that I would have been seeking out if I was looking for this kind of instruction on my own.
I came across this website when I was looking for hands-on student interactives students could do on the computer to practice reading comprehension skills and demonstrate mastery about a topic. The interactives range from ABC match to literacy graffiti for HS. For example, students can create a bio cube that helps students identify and list key elements about a person they are researching and then can print and fold the cube.
This website encompasses more than literacy, but it is so awesome that I have to include it. Mobymax is completely common core aligned for K-8 and is a great tool for facilitating differentiated practice for students and collecting data. It includes reading comprehension practice on passages with quizzes as well as building fiction and non-fiction literacy skills. It will give students a diagnostic test and then suggest lessons from there.