A question to youtube uploaders

I've been using fraps to record and Sony Vegas to edit and render my game play videos. Unfortunately, even though I've been doing it for years, I know next to nothing about it.

Is anyone here familiar with Sony Vegas and youtube and editing/upload gameplay footage with it? What I'm looking for is what setings you use to upload 1080p. What presets (if any) for the project file/rendering do you use? What file type? Etc....

For a while now I've just been using the default settings on projects and then the highest 1080p (25 or 29.9 fps) settings with .wmv format (which limits it to 1440x1080 dimensions). The quality of my videos has been more than decent so far, but I am wondering if there are settings I could use to get highest quality without making files that are in the hundreds of gb's. For example, I rendered a 35gb fraps recording that was 15minutes long at the highest possible settings as an .avi, but it came out over 100gb. No idea why. Is there any file type/setting I can use that will allow me to render at 1920x1080 that will actually compress the file without making the file unwatchable (either due to quality or massive file size).