Blogging
I have the most experience with Weebly. This website and its sister site Jamael's Shorts are both Weebly sites. I like how professional looking the templates are and how simple it is to develop these sites. There is also a link to the Weebly homepage at the bottom of every page of a free version.
Google Sites is also easy to use. I think these look like Wiki pages, which is why I personally don't choose them, but if that's the style you are going for, then Go Google!
Another gem from Google! I actually didn't know that Google made Blogger until recently. It makes sense, it's simple like Google and automatically links to your Google Account.
Communication
Google Hangout is probably my favorite of all the video chat services. I like that it's free, was always meant to be free and doesn't have a bigger and better paid evil twin. You can have up to 10 people on one call and it's pretty sharp technology. It's the little things that make it great.
Skype. Everybody loves Skype. Except I'm loving it less as the years go by. They seem to be taking things away and giving them back, and glitchy and whatever. Maybe by the time you read this, Skype will be amazing again. It's free (for now), and it's good to meet somebody on there that's excited about it. Just please don't get distracted by all the special effects. o.O
I have a friend that swears by this one. I have seen it used before; very clean, simple, and convenient. This one is nice because you can schedule meetings within the program, instead of having to sit in front of your computer waiting.
I discovered Trello recently through my husband, who was introduced to it at work. He's OBSESSED with it now. It's really good for keeping track of To-Do lists, or keeping documentation of an ongoing affair (for example, when we were buying a house, we updated each other on the progress through a Trello card), or even scheduling events like meetings or keeping coworkers in the loop about specific things. I think I still haven't discovered all that Trello can do, and that is exciting to me.
Voicethread is so good for auditory learners that just need to hear their information, either from the instructor, themselves, or their peers. Great for verbal collaboration.
Padlet is such a fun tool for multimedia collaboration. It is easy and free and there are so many types of media that can be embedded. Just check out my Padlet of multiple intelligences about Volcanoes.