Good advice, JD. But I differ with you in a couple of places -
If, in the end your purpose is to create studio quality DVD's from digital then you would do well to figure out a way to come up with a capture card like ATI's Radion family and Premiere Pro with Encore DVD to create your finished product.
Studio 9's DC-10 card will capture analog video and burn to DVD with or without chapter menus, in as good a quality as anything else - at least to my eyes.
I don't know what your definition of "Studio quality" is. None of us, on our home computers, is going to make the same quality as a commercial DVD, but we should be able to get the video quality "up there", crisp and clear.
As far as getting virus's from the Net - that should not be possible today, if you are running XP or W2k and have the latest patches. However, it IS still possible to get Scripting code that plays havoc with your browser, spyware and other nasties. Anyone who surfs the Net and does not use Symantec's Norton Antivirus, is bound to have trouble sooner or later.
If you have the latest patches and you use Norton's, then you're pretty much OK (at least, for now). I'm a web developer and I own a web hosting company. I spend plenty of time on the Net and sometimes even run robot programs to surf for me. Every once in awhile, some jerk will develop a new virus that gets the "one-up" on Microsoft, but Nortons AV is usually "Johnny on the spot" with a fix within less than 24 hours.
I always tell clients to regularly backup their data, keep 2nd and 3rd copies of all program CD's (those disks get scratched, then they're no good) and use our automated backup service for online databases. Data doesn't "go good". Sooner or later, one way or another, all data goes bad.