I like about.com but sometimes the information you need isn't there or it's real hard to find.
I've found interesting websites through google so I consider it a good resource for finding information.
I have a hobby for study and I have come across some nice websites for information.
If you like sword fights I recommend this site.
http://www.thearma.org/It is a website that aims to recreate Medievil Fighting arts that were lost due to disuse because of gunpowder. There are several essays and other material.
For a decent amount of information on the Roman Empire with several chapters with tabs that go into greater detail on subjects.
http://www.roman-empire.net/I love this site because Rome is involved in biblical history and this website has a decent amount of information on early Christianity.
In whatever I am studying, if I have a suspicion that the Romans were involved in some way, I can usually find more detail on this website.
I will use this as a study companion or cross reference.
A guy I see on History, History International, BBC and some others is Mike Loades. Here is a youtube video on British swords in which he gives a brief history lesson and how a sword fight would have actually been. It's in nine parts but it's very interesting.
http://www.youtube.com/watch?v=qEMwcSGauY8I've used this website before for assistance with reading older books like Leviathan. I guess it was originally used as a cliff notes knock off.
It defaults to the literature subject but it has several categories on the left.
http://www.sparknotes.com/sparknotes/It's something to look at for quick notes on some random subjects.