[any ANONYMOUS forum user]

Start out with a high quality sound card, like a Creative Labs Audigy. You can get one without the front panel and other bells and whistles for around 50 bucks. It will come with software and drivers that will give you the option to record from whatever source you prefer.
The "Stereo Mix / Wave-out Mix / What You Hear" option allows to record whatever is coming through the PC speakers, including streaming audio.

However, keep in mind that most streaming audio is lower quality than even FM radio, because of the costs of the increased bandwidth. Once you pass about 128 kbps you have a point of diminishing returns on increasing your fidelity in that the human ear can only distinguish so much perfection. It's generally accepted that most mp3's burned at 196 kbps are cd "quality" even though they really aren't. If I remember right 328 is the highest feasible sampling rate for MP3 files.

To get this in perspective, most streamed audio is 96 kbps or less.

You can record radio stations using lossless formats like FLAC. The results will be identical to stream downloading/capturing/ripping, but you will waste lots of hard disk space.

Another option is to explore the websites of those stations or shows that you enjoy, and to seek out "podcasts", which would be the entire broadcast downloadable in one big gulp, whereas if you are recording live streaming audio or recording on-demand streaming audio from your sound card, you'd need to set it up and it would be running and working the entire length of the program, not to mention, you'd need to be there when it started in real time, unless of course you use a scheduler. Replay AV has a scheduler and allows you to download some streams and records other ones from your sound card. And it even can record from satellite radio (Sirius and XM Radio).