The easiest way is to record your audio program, even if it is using the built in microphones in the laptops, or using a better quality microphone that can be connected via a USB.
Once the recording is done and you are satisfied with the content of what you are saying, you can simply prepare an audio file of it and serve it like a podcast.
Podcasts are easy to host, just like someone would host a music file, you can also use popular services like soundcloud. etc.
A series of podcasts is actually the beginning of an online radio. Once you know that you can produce regular content, and want the extra edge of live streaming then you can decide if you want to take that route.
But trust me, most people cannot get past this stage, while we are all fascinated by Internet Radio, and the technical ease of doing it, we have not really thought out the content strategy.
We have been saying this quite a lot actually, the medium ( be it radio, television, cinema, podcasts or internet radio) is not as important as the message / content of the communication. So focus on that, and the rest will automatically fall in place.
For specific technical queries and further discussions you may please write to us at firstname.lastname@example.org