In one of our PIE meetings, we generated a list of strategies that teachers were finding useful as they helped students become active readers. Here's that starting list; perhaps we'll have time soon to add to it.

Start by looking at the ideas in the article. Be sure students understand the basic premise. Then they can generate an outline or a short summary. At the very least, they should mark the thesis and chunk the text into blocks of prose dealing with related sub-points. In other words, help them see the big picture first.
After establishing the thesis, have students consider what the author hopes to accomplish. By noting the purpose as specifically as possible, students can often see clues to the argumentative structure.
Flesh out some details on the target audience.
Depending on the article, you may want to head students in any of these directions next:
Where are any stipulative definitions?
Do you have questions on specific chunks of text?
Can you note any hidden assumptions?
What are the key examples or images?
How might you synthesize the author's philosophy?
Look at strategies for developing the argument. In particular, have students note definitions, problem-solution statements, causal analysis, process analysis, statement or refutation of the opposition, and specific elements of voice (whining, self-aggrandizement, etc.).

As teaching options, these have worked well for C0CC300 teachers:

Select specific parts of the argument that you want to concentrate on to meet that day's objectives or goals.
Use guided questions. These work nicely in a DAILY or write-to-learn activity.
Try a debate and ask students to evaluate the reasonable and unreasonable arguments that emerge.
Discuss realistic solutions to problems posed in the articles.
Concentrate on one paragraph or chunk of text with a specific purpose in mind. This strategy works especially well to help students understand voice, for instance.
Recycle articles at different points in the term so that you can emphasize different parts of an article. This works especially well after you introduce a new concept or strategy in class.
Play devil's advocate, but be sure to tell the class that's what you're doing so students don't misunderstand your advocacy of a given position.

Use groups to do any of these activities.