Listed on the site are two different ways of viewing the music. First of all, the Sets are collections of tunes which are actually played together. This will generally be the way they are played in the session. A Set may have a recording associated with it. Each Set is made up of a number of individual tunes. On the site these individual tunes can be searched or you can list them all (see the Search page), and each tune may have a separate recording associated with it. There may be tunes on the site which are not yet listed as part of a Set.
To play the MP3s on this site you will need a media player such as Winamp, Windows Media Player etc. You may need to update your player if you have a particularly old version. To download the files right-click on the link and choose 'Save Target As'.
If you have saved a recording to your computer (either from a CD or the internet) you can slow it down by using Windows Media Player (version 9 upwards) - go to View - Enhancements - Play Speed Settings. This is a good technique for getting a handle on the tunes, but take care to listen to the tunes at full speed regularly, as this will give you a better idea of the feel and rhythm of a tune.
If you need to learn by using sheet music or tablature, try to break the tune into small sections. Play your first section using the written music a few times, then try to do it whilst looking away from the sheet. If you get stuck go back to the sheet, but try to keep taking your eyes off the written music. Build up each section until you no longer need the sheet for each bit. If you keep doing this you will eventually have no need to refer to the sheet music at all, which will make it easier to concentrate on your playing technique