GAH! This is my 3rd thread on this, I tried electric guitar and the pit, so now I'm here.
Basically I'm going to get a camera and film myself covering some songs. However, I have questions:
1. I have a 60 wat tube amp and I keep the volume at around 6. How is anybody gonna hear the backing track, assuming I just place the camera on my computer desk, and play the backing track thru the computer speakers? ( I have no other ways of micing stuff, and this is mainly for youtube purposes, not recording.)
2. I need a site where the lead guitar is the ONLY part taken out. I can't sing, I need the vocals left in.

Please help me.
if I turn the amp down the overdrive goes away...... it's a tube amp. Im barely breaking the barrier of distortion as it is.
Play the audio using headphones and record your guitar part to the camera tape or with an interface directly to the computer.

Get the new recording into an audio sequencer and add your backing track to it. Sync the two and then export as a WAV.
Finally import the audio and capture the video into a video editor of your choice, (Sony Vegas is a popular starting program) and sync the audio and video tracks.

It's a tough route to go though if you record your amp using the mic on the camear so I suggest investing in an audio interface and do something like I do.

Record your amp to the computer with an interface (mic it with a SM57 or something)
Record video using a digital video camera (MiniDV is popular)
fix up the audio and export as WAV
Capture the video to the video editor program
import your recorded and backing tracks to the video editor program.

That method will give the best results in terms of sound quality and mix.