Using edmodo in the classroom isn’t rocket science.
Edmodo is essentially an education-focused social media platform. This makes it much less of a headache to use in schools compared to twitter, Google+, or other more popular sites that bring with them various real-world hangnails. You share messages, post documents, and form groups to collaborate.
The presentation below from seyfert6 offers 20 specific ways to get your classroom started, from allowing planning committees to meet digitally, to gathering project-based learning materials or sub plans. If this is not blocked in your district, you may find it useful.