VirtualDub is a free open-source video editor for Windows. It can't do much on the editing side, but it's very useful for doing things like compression, adding watermarks, applying filters, etc.. What I would recommend would be making your video, render/export it, then put it in VirtualDub to put a watermark over. http://www.virtualdub.org/
You do not have to install it, just download and extract it (Right-click zip file, and press Extract). The Watermark filter included in VirtualDub is pretty bad... So install this filter.http://neuron2.net/logo/logo.html
Just download, extract. Copy the "delogo.vdf" file. Go to the VirtualDub folder you extracted, and create a folder (If it does not exist) called "plugins". Now paste the .vdf file in there. Now start up VirtualDub (by double clicking VirtualDub.exe) Go file -> Open Video File.. and select your video. Go to Video -> Filters. In there press add and DeLogo. Now, to make your watermark, use your graphic editing program of choice, and make it. Now leave everything you want see-through/transparent in your watermark white or another color (if so write down the RGB Numbers of it (eg. Red = 255, Blue = 122, Green = 12). Now save it as a ".bmp".
Now back to the VirtualDub. In DeLogo open your .BMP file, and check Transparent Color. For white, enter R: 255, B: 255, G: 255. For another color, you'll have to enter something different. Tolerance means how much can the color be different of that to accept. For instance if you have a tiny tiny spec of a light light gray, Tolerance at 0 it won't say it's transparent. But if it was a higher number then 0 it might. But if it's too high it will make what you want in the watermark transparent.
You can mess with the other options if you want. Now, all we have to do now is set the compression of the video, so it doesn't end up as gigabytes when you export/render it.
To compress it, go to Video -> Compression and select what codec you wish and configure it. Talking about compression in this thread, would be very hard. Leave all the settings of the codec normal, but make sure to have the bitrate at 500-4000 KB/PS. The higher the bit rate, the better the quality but bigger the file size. If you don't have any codecs or any that work in VirtualDub you can go and download a free codec called X-vid. http://www.xvid.org/Downloads.15.0.html
Now to finish it off go to File -> Save AVI... and put in the name and wait a bit.
This may seem a bit complicated at first, but don't worry this will teach you a lot about video editing in general. I wish you lot's of luck in your YouTube videos, when you're done post a link, I would like to see it. If you need any more help just reply
Edit: Also make sure to do some tests, this will save you pain and agony when something goes wrong.
If you rather not deal with all that stuff above, and if you're using Windows Movie Maker, try just adding a title over, and messing around with the font properties.
Edited by RubixNG, 16 March 2010 - 10:44 PM.