I really have no idea if this belongs in guitar techniques haha, but what I want to know is how to make my guitar sound distorted, but not dirty (no extra noises, notes ringing out, etc.), like many videos you can see on youtube. I realize lots of the time the video and audio are different takes, but how do they record the audio so professional sounding? Is it a technique or equipment?
Both. You need to make sure you can play cleanly not recorded (Muting strings, etc.)

A mic will give you the best sound quality, sometimes even improving it.

Go buy a Shure SM57, its probably the most commonly used mic of all time, and its only 100 bucks. A combination of technique and some recording equipment will sound clean and flawless.
Where's Waldo?
+1 to everything chad said, especially the part on getting an SM57. Worth it's weight in gold when it comes to recording guitars. Needless to say playing clean is extremely important to..

Just wanted to add that those videos you are talking about will sometimes use some form of editing to further perfect their sound. Stuff like strip silence will take out ambient noise and buzz/hiss from an amp while you can also EQ to dial in the exact tone you were looking for.
You can find your answers in the recording forum. Audio and Video are shot at the same time(when I do it at least) . My camera provides the video and my guitar is plugged into my PC using an interface(M-Audio Fast Track) which records the AUDIO in a DAW(recording/editing program). Once you have the two files recorded you can just edit them using windows movie maker by dubbing the recorded audio over the video.
Hope this helps.
Last edited by dopelope at Jul 21, 2011,
It's a combination.

Good technique is absolutely a must. You can do a lot of studio trickery to make up for bad technique, but you don't need nearly as many if you have good, clean technique.

Good equipment is absolutely a must. You could be the best guitarist alive, but using a cell phone camera to record your epic playing will only sound bad.

A number of players I know of use direct-input equipment to run their rig directly into the sound card of their computer. That results in a low-latency recording and minimal mic buzz and whatnot. There are a number of ways to do that. I use the Toneport UX2 for my recordings, which gets me pretty good results. Check the links in my sig for confirmation.

If you want to get rid of notes ringing out and all that, that's a technique issue. That's something that you can fix on your own. Good sound quality is an equipment issue more than anything. A good directional mic or direct-input equipment is the best way to get good results.