CCR Standards Resources
Free, reproducible student activities aligned with Common Core State Standards (CCSS) for Reading Foundational Skills (and other ELA standards). They are organized by grade levels (K-5), provide teacher pages outlining objectives/materials/steps, and include student pages without a childish appearance.
The site describes itself as "full of free content designed to help educators understand and implement the Common Core and other college and career ready standards." Resources include CCRS-aligned lessons, activities, assessments and more, but also materials to support educators in understanding the standards and the content.