I completed the RN to BSN programme about a year ago. I had to complete 44 units. Was able to complete 26 units the first term, then completed the final 18 units the second term. It's actually a pretty straight foreword experience. Most of the classes will have you do a project or series of projects that you turn in for grading. It's pretty much pass or fail but the rubric is very specific and if you follow it you will likely succeed. A few of the classes mandate that you take an exam that you will have to set up through an approved site, or you can take at home, but somebody watches you through a webcam.
The general flow is as much or as little as you make it. You have to complete 12 units a term to stay in good standing however. I would recommend going all out if possible, because you pay by the term and not per credit/unit. I was told most people take about three terms to complete, but going hard can be the difference between a $6,000 degree and a $9,000 degree. Additionally, you will be talking to your mentor quite frequently during the first month or so during the first term, but that will eventually die down to once every week or two as long as you are making satisfactory progress. I would strongly recommend you make sure that you are very comfortable writing papers using APA format because you will spend a good portion of your time writing papers.
All in all, it was a fairly painless experience. Do not expect to have significant freedom in how you will do your assignments and what topics to choose, particularly when you are doing the nursing courses. There is a formula for success and you would do well to stick with it even though it does tend to limit creativity and out of the box thinking.