I really loved the allusion to The Wizard of Oz here. Differentiation does feel like the wizard, and this article "lifts the curtain" and gives real, useful tips to find easy and effective differentiation methods for diverse learning styles. I also really resonated with the idea of processing time, since I think everyone does need just a few minutes of downtime to process heavy blocks of information, but schools don't always give that option.
Although this resource discusses diversity at the university level, there is a lot to learn from it for K-12 educators as well. We often have an idea of where students "should" be based on the state's or district's education standards, but we don't always stop and think about other invisible factors such as students' backgrounds, attitudes toward education, and learning styles. The questions this link urges teachers to ask themselves are valid and useful.
This resource aims for an elementary school audience, but some of the lessons are useful for the entire K-12 spectrum. Racial and cultural biases and prejudices are sadly very common today (especially with many recent news stories), so these tips can help bring schools for the next generation into a more inclusive space. This definitely can't hurt to help make long term social changes.
A professional development module that examines the roles of culture, race, gender, etc. and emphasizes the importance of recognizing them as teachers. The module also considers that some lessons, which are effective for some classes, may not sit well with different groups of students, which is a concern that can happen to teachers anytime. There are also some fascinating case studies and statistics that you can learn and use to inform your teachings.
This site compiles a lot of lesson ideas and tips for teaching English Language Learners in the classroom. If you're lucky, you will also have a great and supportive set of ELL support staff to help you out, but even if you don't, this should help you reach your ELLs better and give you insight into some of the laws and policies that support ELLs.
This is a chapter from a larger book, which is available on the site for purchase if you want. However, this free chapter alone is a gold mine of tips, tricks, and data about "the achievement gap" and gives some ideas for how schools can better serve their minority students in closing this gap. It's a longer read than some of these articles, but it's worth it for the insight.
This article is a great resource, as it offers suggestions and solutions to some differentiation problems using technology. Not only does this help with the all-important 21st-century skills that we as teachers are told to emphasize, but the technology can facilitate differentiation and diversity in ways that traditional textbooks and resources could not. There are also some handy resources that the creators selected and recommended for specific challenges because they found them to be useful.
An adaptable method that is a really useful way to get the usual "ice-breaker" information at the beginning of class, but also add a dimension of student-reported strengths and weaknesses that the teacher can use for later differentiation and give the teacher a better sense of the classroom's overall diversity. I wouldn't rely solely on these cards, but they're a good survey technique and a good start to a year.