Effective Instruction for Middle School Students with Reading Difficulties: The Reading Teacher's Sourcebook - This 410 page guide is an excellent resource for teachers of grades 5-12. Many interventions are included.
Strategies for Reading and Spelling Multi-Syllabic Words - This document contains interventions to help students count and identify syllables, understand open and closed syllables, and read and write multi-syllabic words.
Reading Interventions Manual - A manual written by Jim Wright called The Savvy Teacher's Guide: Reading Interventions that Work.
Meeting the Needs of Struggling Readers: A Resource for Secondary Language Arts Teachers - Good resource for strategies and interventions for grades 5-12.
Mosaic of Thought Website - A listserve with various tools to use that emphasizes the philosophy of comprehension strategy instruction outlined in Ellin Olvier Keene and Susan Zimmermann's book Mosaic of Thought.
Arkansas Literacy Intervention - The Arkansas Literacy Intervention Matrix is a resource consisting of instructional materials for grades K12 addressing the five essential areas of literacy: phonemic awareness, phonics, vocabulary, fluency, and comprehension, plus two additional components--oral language and writing. Follow the links under Literacy Intervention Matrix.
Florida Center for Reading Research - This site contains multiple interventions for the five critical areas of reading.
Intervention Central offers free tools and resources to help school staff and parents to promote positive classroom behaviors and foster effective learning for all children and youth.
Orton-Gillingham Approach - This site has resources to help you understand the Orton-Gillingham approach to teaching struggling readers and the structure of a lesson.
Tier 3 Programs - This site contains resources to support effective interventions.