[BcY]

Code:

#include <amxmodx>
#include <amxmisc>

#define PLUGIN "New Plug-In"
#define VERSION "1.0"
#define AUTHOR "author"


public plugin_init() {
    register_plugin(PLUGIN, VERSION, AUTHOR)
    return PLUGIN_CONTINUE
}

public plugin_precache()
{
    precache_generic("sound/sound.mp3")
    return PLUGIN_HANDLED
}

List your sounds like
precache_generic("sound/sound.mp3")
precache_generic("sound/sound2.mp3")