Though the focus of the label is on IDM and experimental electronic music, the filesharing software includes all styles of music, IDM being particularly popular (along with indy rock, underground hiphop and other burgeoning independent music scenes).
The P2P client itself is somewhat conventional in that you can search for files, and it's somewhat like Direct Connect in that you can browse users' files and chat.
To me, the search functionality is less useful than simply going to a chatroom for the style of music I'm interested in (I spend a lot of time in Jazz-Full CDs), and either asking what's new, or manually browsing fellow users in the chatroom. You can find a great deal of unreleased and independent material this way, and people are surprisingly helpful at offering suggestions.
You can download the latest Soulseek client for free at this address: http://www.slsknet.org
Note that this is the only valid site for downloading it; all the other sites are fakes, which will infest your computer with spyware. Be careful as 3rd-party spyware companies have created fake Soulseek homepages at all the variations of the above address (slsknet.net, slsknet.com etc) ... So, make sure you're actually downloading it from slsknet.org, the real Soulseek homepage.