Here's a potpourii of experience I've picked up over the last couple years making multimedia files. Perhaps something here will help you. Go here for even more. If you have a specific problem, search Google or email me. All the major multimedia vendors have helpful suppot forums where users can get their problems solved. I have used these many times to get help and give help.
You will have the best experience if you start out with a new, powerful computer, low-end software, low expectations, and your videos are short (less than 15 min).
o What software should I use? Start out with Movie Maker (Win XP) and switch to a low-end product after you get the hang of it. Search Google for lots of free video editing programs. Ulead, Pinnacle, Macromedia, Magix. etal. all produce entry-level products. Also, you may be aware that Nero and Easy Media Creator both have video editing programs embedded in them.
I use the medium-skill level Pinnacle Studio10 (~$200 with analog/digital capture card). I have purchased a wide range of extra transitions and effects and use a slick background music generating program that's embedded inside Pinnacle.
o Why does my computer crash when I edit or preview a multimedia file? This is a common problem. Multimedia computers need to be clean and mean to do the best job of laying out, editing, previewing, and rendering a file. Apparently, all the programs and crap on our computers get in the way of the computer when it syncs up and puts everything together precisely time-wise into a multimedia file.
o Why does my computer crash when I render a multimedia file? This is a common problem. This happened a lot to me in the beginning with a 500 MHz Dell PIII laptop with 448 MB RAM. Sometimes when I repeated the render, it might go ok. I think the answer is that the computer has too much to keep track of and it's too weak for multimedia. I've since purchased a Dell Dimension 8250 (3.06 MHz CPU, 1.5 GB RAM, 200 GB HD) just for video editing. I render each chapter of a 60 min. DVD into a small, separate .mpg file. Then, I put all the chapter .mpg's on the timeline and render to the final DVD. This approach always works since the hard computer work was done making the separate .mpg chapter files rather than rendering all the stuff together on the timeline all at once.