If you are just looking to render in 720p (which in my opinion is all you need when watching on a regular sized PC monitor) then this is what I use when rendering all my videos!
First off, when you insert a video clip in, you wanna right click > properties > disable resample
That will stop your video from looking ghosty. (Adding in extra frames)
Next when customizing your template, om the audio tab you will need the following:
Include audio - Yes (Pretty obvious)
Mode - CBR
Format - Windows Media Audio 9.2
Attributes - 192kbps, 48 KHz etc.
Video tab:
Mode - CBR
Format - Windows Media Video 9
Image Size - High Def (1280x720)
Pixel Aspect Ratio - 1.000 (Square)
FPS - 29.97 (NTSC)
Seconds per keyframe - 5
Override default etc. - Yes
(seconds) - 3
Bit Rate tab:
Tick Internet Lan and set to 6M
Index/Summary tab isn't really important
Project tab:
Video rendering quality - BEst
Stereoscopic 3D mode - (Use Project Settings)
And that's it really! Sorry if I missed something out but i am using a different version of Sony Vegas but that is the basic guidelines and I am sure you can work from it!
-Gman