I'm not trying to start a war or anything, I just want to make sure accurate and useful information gets out. To say that (note the quote):
You shouldn't use 640x480(Too small) or 1024x768(Too large).
Use 800x600 screen resolution. It's the best. Most used nowdays.
is merely your opinion. Did you do a survey to see what was the most used resolution? I haven't used 800x600 in any game in about 2 years on my newest PC. My old one won't play some games in 800x600 at a decent frame rate as it's pretty crappy (mostly just used by my son for surfing). So in both circumstances your information is not accurate. It's not necessarily wrong, just not totally true.

Here's what I would say:

You may want to have a default resolution of 800x600, but you should always give the user the ability to change the resolution to whatever works best for them.