How to build a simple blog where content could be published securely to user groups? I am developing a PHP application and want to host a blog to communicate with my alpha, beta, and (hopefully) other users.  I have some experience with Drupal, so am planning to put it to use.

I installed Acquia Commons.  It was impressive, perhaps too impressive for my needs.  I started out by trying to remove some of the features, and I found that there's not much documentation freely available for it.  (I don't want a paid service - this startup has not made any money).

I am thinking that Drupal Core with Organic Groups added might be sufficient, but I'm not sure since I have not used Organic Groups before.  And of course, there could be other distributions or modules that I don't know about too.

So, the question is, if your Drupal skills were pretty basic, how would you go about building a simple blog where content could be published securely to user groups?

EDIT: Maybe my usage of the word 'groups' is confusing the issue.  Perhaps I could do this simply by creating different roles, such as Alpha User, Beta User, and assigning users to those roles.  In that case, how would I go about restricting access to content based on role?
As per your "... there could be other distributions or modules that I don't know about too." in your question: have a look at the Group module (commonly perceived as an alternative for Organic Groups).

Group allows for creating arbitrary collections of your content and users on your site, and grant access control permissions on those collections. It is available as of D7, and has a D8 version also. The Group module creates groups as entities, making them fully fieldable, extensible and exportable. Which also makes it integrate very well (out of the box) with commonly used modules such as Rules, Views, etc.

Some more questions you may want to look at for more details:


What are the various roles supported by the Group module?, which explains the various types of roles that can be used. 
How to bulk assign existing content to a group created with the Group module?, a typical issue when adding this module to an existing site).
What are the features of the Group module versus Organic Group module?


Resources


Community documentation for the Group module.
Video tutorial "How to use the Group module in Drupal 8 to manage editorial access control to different areas of a web site".