I am using a xenyx q1202 mixing board and i am having trouble figuring out how to record Youtube and mic audio at the same time on audacity. If anyone could explain what i need to do it would be very appreciated. 
Sure. That’s how I did my Skype Podcast test.
Connect the headphone or stereo line-out of the computer to one of the line-In connections on the mixer.
The microphone is pretty obvious.
Connect the Tape-Out, Line-Out or whatever your mixer has to the Stereo Line-In of the computer. There’s almost no chance you have one of those, so you will need an adapter such as the Behringer UCA-202.
I cheated. Both of my Mac laptops have Stereo Line-In.
Set the browser or Windows to play to the laptop headphone connection and that should appear in the mixer. That’s pretty normal. Here’s where it’s tricky. Set Audacity Device Toolbar to record from the laptop stereo Line-In (if you have one) or the Behringer UCA-202 if you don’t.
http://manual.audacityteam.org/man/device_toolbar.html
The Behringer will appear as “USB Audio CODEC” It doesn’t say Behringer. The whole mixer show including YouTube and local microphone should be recorded in Audacity.
Koz
In the case of the podcast test, I played a music player out of the laptop into the mixer and that’s how I got my background music for the show. The other side of the laptop recorded the show mix—both at once.
Koz
Attached sample sound clip.
Koz
If you have a 1202USB, you won’t need the extra USB adapter.
Koz
so since i have the 1202usb i wont need the adapter. so what do i do then?
In the Audacity Device Toolbar, search for the Mixer’s USB identity instead of the Behringer (USB Audio CODEC). I have zero idea what the words will say. They’re not standard.
http://manual.audacityteam.org/man/device_toolbar.html
If you’re totally flummoxed, disconnect the mixer, restart Audacity and make it show you it’s recording list from the dropdown (microphone picture). Just make a note of it. Plug in the mixer, wait a couple of seconds and restart Audacity. Look at the recording list again. There should be one thing there that didn’t used to be there a minute ago. That’s your mixer.
Audacity will try and record from that device if that’s what you select.
You still have to set Stereo and a supported sample rate, probably start with 44100.
If you’ve been poking at this for a while, you may have some settings wrong now. They will show up when you try to make a recording.
Were you able to play YouTube sound and see it on the mixer? This show is really two different jobs.
Let us know.
Koz
Thank you very much for you help. i got it working! 