Connect to internet via a dial up. Because of distance and/or dubious quality phone lines, get 26,400 to 28,400 bps connection.
Norton Antivirus updates automaticly, although I do a manual check occassionly. I think the reference file(s) are usually within at most a few days of the current date.
Re: Windows 98SE. I purchased the computer about 4 years ago from a local shop. It was a package they put together. The specs were good enough for my purposes, at a reasonable price, and I got to support a local business. At the time, they were suspicious of the later version of Windows, and were sticking to the "old reliable 98-SE". They have long since quite putting out their own computers, since they can't compete with Dell etc. I have been doing the Windows 98 updates from Microsoft. It seems you need to have IE for that, if for nothing else.
Do use Outlook Express. Probably really should ditch that and go the the Mozilla offering.
I like to use Startup Inspector. Start it and (being connected to the Internet) click "Consult". It'll be able to tell you what most startup programs are for, and classify them as critical, useful, optional, and not recommended (with some "unknown").
For those of you who have trouble with windows, I strongly recommend Linux Ubuntu: Warty. The up side is everything microsoft has (including .net and other really expensive softwares) ubuntu has. Whole thing is free. It's is about twice as stable as windows xp. You could never get a virus or spyware on it. The downside is you have to be computer literate to be able to use it. Newbies will probably cry trying to find out how to install programs.