To use music files with Sound Mill, you first need to 'Rip' (copy) the music tracks from a music CD to your computer hard-drive. It is a fairly simple process. You can select the bit rate when ripping tracks. We recommend a minimum bit rate of 192 kbps for sufficient fidelity. Higher bit rates create better fidelity but larger audio files. Try ripping at different bit rates and test the audio on your system to find the best trade off. You can select any rip format, MP3 is probably the most popular. Your ripped CD is placed in your My Documents\My Music\ folder by "Artist Name\Album Name". Once the files are there, you can drag and drop the files into a Sound Mill sound list.
Complete instructions on ripping can be found at the Windows Media Player 11 How-to Center
[for Vista],
[for XP]. But you can use ripped audio files from any music player you prefer.
Check you local library for sound effects CDs or enter Google search phrase "sound effects" to find audio files available for download (many are free and have public domain usage and copyrights). The well equipped sound person should have at least one Wav editing utility program. Here are a couple that are free and simple to use. There are others if you dig around the Web a bit.