bugi, Your player works the same as a USB drive so the easiest way to transfer files to your player is to use Explorer and copy and past the files from your music library to folders on your player. If you want to remove files from your player just enter the player through Explorer and delete the files to make room for others.
You can also create a shortcut to your players music folder and leave it on your desktop, then you can just drag music files from Explorer and drop them on the desktop shortcut. You could also put the shortcut into your Send To folder which you will find in C:\Documents and Settings\User*\Send To (Use* being your user name) As the Send To folder is hidden you will have to click on tools in the Explorer menu bar, select Folder Options, View and then select Show Hidden Folders and Files then apply. Once you have the shortcut to your players Music folder in the Send To folder you can just right click on any music files you want to copy to your player and choose Send To from the popup menu and you will see the shortcut to your player.
There is also a simple music sync program you can download
HERE