MacBook to T.V.?

I have the new MacBook (Aluminum casing, but NOT McaBook Pro) and I want to display some home videos and various school projects on my T.V. I have an LCD T.V. (LG Brand) With HDMI. Right now my setup is as follows:

-Mini Display port to DVI adaptor-DVI to HDMI Cable-LG T.V.
MacBook
-3.5 mm sound jack to RCA Cables-LG T.V.

When I change the T.V. input to read the HDMI, all I see is my destop photo but not any of my open windows, dock, etc. The guy at Bestbuy told me I had to schange my display settings to "Duplicate Display" or something like that, and I've been foolling around with the settings but I can't figure out how to get it to work.

One more thing that might make a difference; on the back of the T.V. there are two HDMI ports, one is just HDMI in, and the other is HDMI to DVI in or something like that.

Hopefully someone can help me out with this, as I just shelled out about $100 for the proper cables. :S

Thanks in advance for any help!
-Stefani

You spent way too much on cables, but that's another story....

1st - Check the manual for your TV to see which HDMI input you should be using for what you're using it for.

2nd - Go to System Preferences > Displays > Detect Displays(bottom right) > Arrangement > (You have 2 options here)...

Make sure "Mirror Display" is unchecked. You'll probably just have a blank desktop on the TV at this point. All you do is drag your window(s) from your MB onto the tv screen. Move the cursor to the right or left until it shows up on your MB screen and drag the windows back the other direction to your tv screen.You can dim your MB screen to black or close the lid and wake it up with an external mouse and keyboard.

OR check "Mirror Display" and whatever you do on your MB will show up on your tv. But I prefer the other method. Try it out and see what works best for you.