Hi Podcasting is simply broadcasting yourself over the net - it doesn't take much to do.
Firstly - you'll need a microphone (pic one up from Argos for a tenner) a headset is a good idea too because you wont experience "echoing" as much.
Connect it to your soundcards microphone port, and make sure it is not muted in the soundcards recording settings (around half way on the mic volume settings is fine).
Next, you'll want to record your audio. A program which will simply allow you to record and edit audio is Audacity - a free Open Source programme. Record it as an mp3. This will require an additional plugin - called Lame MP3. A download is available from the Sourceforge download site - just google Audacity and you should get all the links you need.
Hosting - if your ISP provides web-space you can use that. Companies also provide specific hosting solutions for podcasting but I cant remember the names of any - again google it. Any webspace with a decent bandwidth limit is ok.
It is against UK law to broadcast copyrighted music without the correct licenses from MCPS PRS and PPL which is costly - and complicated. The podcast should really only contain voice without music - unless you own the material or have gained permission from the respective owners.
Hope this helps