This question is basically about copyright and how to find compatible music for videos that amateurs can use without getting in trouble with Youtube (or other video hosting websites) Terms of Service policy's.
The use of any copyrighted music is strictly forbidden on youtube, even a few seconds of copyrighted music can bring big trouble. Youtube can remove all the audio from your video or even delete the video entirely.
You can find alot of music on the net, but you must find original music that the artist/musician specifically allows use, preferably with a Creative Commons licence.
I have settled on two musicians that I use for music on my videos
I prefer instrumentals and both Dan O'Connor and Josh Woodward have outstanding instrumental only music. Josh, who is an excellent vocalist and songwriter also provides all his songs (over 170) with and without vocals. Look for the link to "instrumental version" for each album.
Dan likes to see what your project looks like using his music, and asks you to post a link to your project on his Facebook page.
The Creative Commons Attribution Licence requires that a link be placed on the video itself, as a credit somewhere in the video (I place them at the end). I also put links to the musicians websites (and Facebooks, Myspace, blogs, youtube channels and twitters). I keep a text document for each artist with so I can cut and paste all the links and other information quickly and easily. Each artist is different and the information they require as an attribution is spelled out on their websites. You should look for music that the musician allows commercial use with only attribution. Youtube may ask you to monetize your videos by placing relevant advertisements on the page where the video is hosted or on the video itself using a pop-up ad. If you make a profit from your video, it's only fair that some of the profit be shared with the musician. If you use music licensed under a Creative Commons non-commercial use licence, the original creator of the music does not allow you to profit from their work and you cannot monetize your videos. So remember, you're looking for music that the original creator allows used on a "Creative Commons, Attribution, Commercial Use License".
Jamendo ( http://www.jamendo.com/en/ ) is another website that has a very large section of music under a Creative Commons licence. Go to the Jamendo website, click on the music tab, then scroll down to Creative Commons . You can find tons of different genres of music, alot of which is under a commercial, attribution, Creative Commons License. Personally, I would contact the musician or band and ask if their music is available for use. I've been happy with the music of Dan O'Connor and Josh Woodward, but I've checked out some of the artists on Jamendo and will probably use them at some point in the future.
When I am done with this bicycle tour, I intend to make a multi-part video explaining the process of making video documentary of a bike tour. I have learned alot about video editing in the last year and I want to share the little tips and tricks I've picked up along the way.