Anyone have good resources for learning actionscript 3.0?

I was trying to make a flash that:
-plays a song once it starts
-has a button that plays the next song of possibly 3 or more songs and stops playing the previous one
-a button to increase the volume
-a button to decrease the volume
-a button to stop all sounds

Currently I've accomplished:
Playing a song once it starts and a button o stop sounds.

I've tried implementing some examples that I found but I couldn't get any noticeable volume changes to work.
I'm thinking of putting the sounds into a linked list and retrieving them that way in order to switch them, but it seems inefficient when I'm going to have a finite and small amount of songs.

import flash.media.Sound;
import flash.media.SoundTransform;
import flash.events.MouseEvent;
import flash.media.SoundChannel;
import flash.display.MovieClip;

var current:int = 0;
var songs:Array = new Array(new ExportedForActionScriptDotWav(), new SecondDotMp3(), new ThirdDotWav());

var st:SoundTransform = new SoundTransform();
var chan:SoundChannel = songs[current].play(current, int.MAX_VALUE, st);

function prepare(mc:MovieClip) {
    mc.addEventListener(MouseEvent.CLICK, clickResponse);   
    mc.buttonMode = true; //change mouse cursor on hover to the hand version and makes tab work for selection
}

prepare(movieClipNamedVolUp);
prepare(movieClipNamedVolDown);
prepare(movieClipNamedNextSong);
prepare(movieClipNamedStopAll);

function clickResponse(me:MouseEvent) {
    if (me.target.name=="movieClipNamedVolUp") {
        volumeChange(1.2, 0.01); //precision increase
    } else if (me.target.name=="movieClipNamedVolDown") {
        volumeChange(0.8, -0.1); //quick decrease
    } else if (me.target.name=="movieClipNamedNextSong") {
        chan.stop();
        current++;
        if (current==songs.length) {
            current = 0;
        }
        chan = songs[current].play(0, int.MAX_VALUE, st);
    } else if (me.target.name=="movieClipNamedStopAll") {
        SoundMixer.stopAll();
        current--; //will replay current song when next is clicked
        if (current<0) {
            current = songs.length-1;
        }
    }
}

function volumeChange(multiplier:Number, steadyAmount:Number) {
    st.volume = Math.max(0, Math.min(1, st.volume*multiplier+steadyAmount));
    chan.soundTransform = st;
}

I looked in a debug window and it seems to line 14 which is:
mc.addEventListener(MouseEvent.CLICK, clickResponse);

Also I had to put a "this." in front of each movie clip name inside of the prepare() calls, otherwise it would give an error #1120 for each one.

Thanks for your help so far!

You're getting null reference exceptions because the variable "movieClipNamedVolUp" doesn't refer to anything, once you've done the above you can once again remove "this." that you added. The problem is still there, "this." just tricks the precompiler to think everything is fine and the problem is instead discovered at runtime in the prepare() function. Flash's precompiler is a little so-so.

What happens when you drag a MovieClip to the stage and set its Properties' "Instance name" is that Flash prepares a variable by that name, set it to equal the instance and then makes the variable available to ActionScript as long as that frame is visible on the timeline.

It's working now, thanks!