I have a sony camcorder (HDR-Cx550v). I haven't used it even one time, so I know nothing about making videos (zero). I want to buy some video editing software to cut out sections I don't want and attach the two ends I do want. I believe the camcorder can record in the fairly new avchd format. Vegas pro 10 cost $500 and if it will help me a lot I'll buy it but Amazon reviewers said it has a lot of stability problems. Vegas Movie Studio is only $60. Let's say they both have no stability problems. There's so much terminology in video that I don't know that I can't tell what either of them do, when would I want one, when would I want the other? Are there other software programs that will work with Sony camcorders that I should be considering? I really want the file(s) the software creates to load fast so the video player doesn't have to stop playing to wait for the file(s) to load.
I'd start with Windows Movie Maker or iMovie depending on what kind of computer you have -- they both handle that sort of linear editing pretty well.
Insofar as making the files load fast, that is largely an encoding trick. If you are putting them on the web, you probably want to use a proper video platform. Youtube is a great place to start actually.