As far as visual editing goes there is another question I recently answered "free editing software?" you may want to look into that.
Sound can be added in several basic programs such as moviemaker for windows which I believe is free.
To edit information about a song right click on the songs title and select Get Info from the menu. In the Info box you can add information about the song; in Sorting you can say how you want the song sorted in your library, and add lyrics and artwork.
Try windows movie maker. Or go to My videos, and click edit next to the one you want to edit.
U get the URL of the video. Then go 2 gaia and click on edit profile layout. Next, u go 2 content and add media. Click on edit, of the media, and add the URL in. U can have as many videos as u want! :) my name is: IM_THy_B0mb
Magic Camera is an app that is used to edit and customize pictures or video. To add the web cam effects you must go into the setting and apply the effects that you will like to add to you picture or video.
Go to my videos find the video you want to edit click on the annotations button.
There is an inbuilt editing tool which allows you to edit the length of the video but for the best editing you would need to download iMovie from the app store and use that to edit and add stuff to your videos.
Edit - song - was created in 2006.
When you make your video, put it into a video editor (even one as simple as Windows Movie Maker, which comes on all Windows computers) and add the song of choice to the timeline in the music section. If you have trouble, then message me.
On a personal page: On your home page next to your main pic, click on "edit profile" -- on the far right of the tabs, it will read "song and video" click there. On a music page: On your home page click on the tab which says "edit profile" then click on the "edit songs" tab.
when you have found the song you are satisfied with. Click on the addition sign and it will automatically ask if you wana add the song to your playlist or as a single song. you can click either one.
It took Chris 1 month but he learned the song lyrics backwards to add effect to the video!
Once you upload a video onto YouTube, it cannot really be edited any more. You can only add annotations to the video, add branding, and/or replace the audio of your video with pre-approved YouTube audio. If you want to trim a song (which might still get you a copyright strike), it would be best to do it in video editing software before uploading the video onto YouTube.