(Some useful, some interesting)

(Not what you might think)

Help fight disease without doing anything!   They use your computer idle time to calculate molecular designs, it does not slow down the machine, I have been with this for several years.  If you want more info look at 

5 Star Support A source of technical help (If I have not been able to help you!)
Julie's page Part of the web site devoted in memory of our daughter Julie, who died tragically a few days before Christmas 2004
A Thought Provoking Moment What it says, a very pleasant site which offers many free goodies

A huge repository of software, some of it free - has a search option so you can look for exactly what you want.

Cnet Another good source of software, particularly trial versions of the big stuff - some free ones there to. Also has search option.
Shareware A source of some free and shareware programs divided into categories - some good games and educationals in here.
Webshots A good source of images, wallpaper and screensavers, all free.
Thundercloud An excellent site for wallpaper, screensavers etc, and also they produce a very helpful computer newsletter!

I will add more as I think of them!