There are many different platforms that can be used for creating a digital classroom portal. The one you choose depends on the purpose you have, ie What do you want to do with the portal?

Once you have answered that question then you can think about the tool that you want to use. At our district we will be mainly focusing on the following tools, although again depending on your purpose you might need to choose another tool to fit those needs.

eSchool: This is our student management system, and if all you want to do is provide home access for your students and parents to view and access assignments, documents, and grades this might be the only thing you need.

For Vestal's Domain:

Resources for Edmodo:
Using Edmodo in a K-12 School
Edmodo for Teachers Guide
Edmodo, Yes!
15 more brilliant ways to use Edmodo
7 Quick reasons why Edmodo is great
Chilton's Edmodo Resources


Schoology Instructional Guide (everything you need to know...)

Blogs allow teachers and students to share, collaborate, and have great discussions.
The best blog platforms to use:
See my blog platform comparison for more information on the platforms.

If you are looking for a place where you can add resources (like I have done with this wiki), as well as allow others to collaborate and add resources, a wiki is a good tool to use. I like wikispaces.
This is a great way to have an easy portal that you can then link off of.
Yes, you can also embed a calendar within the wiki. To see how edit your page and click on 'widget', 'calendar'. To embed a google calendar follow the steps there. I have created a sample calendar here.