I'm going to give a two hour workshop on a programming topic (NHibernate). It will be a small group, of around five people. The attendees will all have their own laptops.
What would be the best way to structure the workshop so that the attendees get an insight into the topic and preferrably don't fall asleep?
Add a few (or just one!) hands-on lab(s) into the mix. You could burn it on CD or whatever, hand it out at the start and they can all load it up and play along and run it. It just means you need to put some effort in, in terms of creating the template project and to ensure they just have to fill in a few things/gaps here and there, and it will run without a problem.
During your presentation you will then have 'Hands-on lab intervals'. Where you go through some of the steps and let the candidates fill in some of the pieces of the puzzle.
That way, you can let them fill in the appropriate gaps that you think are necessary in order to "get" it. And at the same time, it ensures the attendees won't fall asleep, as they actually actively participate.
I think the most important thing to keep in mind is that your attendees are going to have different learning styles. What I would do is create a slide-show or outline that gives the skeleton of the topics you want to cover. Then create the code examples you want to work from based off of the topics. Once that is done create your solution code files to all of the examples you made. Ideally, you will want to give all of the attendees a copy of the material when they show up. This way they have something to following along with and if they get ahead or fall behind they have the material necessary to still learn. Finally, make sure you practice your presentation. When you practice it you won't want it to take the full 2 hours because you will want to leave time for questions. It also could help if you mark on your outline how long it should take you to get to each major point. That way you know if you are staying on pace or not.
I don't know if you can get a black-n-white answer here, but definitely there's opinions on how to best engage your audience...
You will probably know your audience much better than I do, so you're in a better place to make this determination. I'll assume your attendees are going to be developers, due to the topic you'll be presenting.
And here's my personal opinion: "what we learn to do, we learn by doing", right? So, go with some hands-on exercise. For instance, look at the NerdDinner tutorial online to see how you can have them 'build' something while exploring the features of NHibernate you wish to expose them to.
I also reccomend making sure one of the exercises is more similar to a 'maintainance' task instead of a 'create from scratch' example since people will eventually spend more time in the former rather than the latter mode. SO perhaps have an exercise or two for them to do from scratch, and then have a prepared 'code base' they'll have to modify.
HTH