Um...I think this goes here in WD, I think it's writing related... if it's not, sorry.
Anyway, my favorite way to learn about history is to watch History Channel DVDs (of course in some cases you're getting the secular version of history, ), from which I learn about weapons, techniques, and other things that can inspire new fantasy inventions as well as emulate real-life weapons/machines/tactics/etc.

For example I'm going through the History series of DVDs called Rome: Rise and Fall of an Empire which is full of awesome (usually not noticeably cheesy) re-enactments (that I think stick fairly close to what they "know" happened from records and stuff, though I'm sure they make it more dramatic and take a little artistic license) and really imprints on your brain what happened there and (here's where it applies to writing!) what could happen in your fantasy world in some form or another!

All that to say, I'd like to make a bit of an index here with links to helpful/inspirational/educational videos that can stimulate your writerly imagination!
But of course I need other people to add things to it, so if you've watched a video about weapons, warfare, or history that you think could inspire something in an author (basically anything can, but hopefully stuff here will do so more specifically than, say, a Daffy Duck cartoon would), please post a link to it here with a short description or summary of it and how it helped you. When we've got enough stuff here, we'll have a slightly categorized index of video resources (if people think this would be a useful thing that could go here).
If you have the powers necessary, you can add your own submissions with a note describing them. If there is a lot of violence or any other possible concern, please list it in the note.
(Only click spoilers if you want a description of what you might see that could be offensive or revolting. To click an in-note spoiler you click on the note bubble and then click on the spoiler.)

Weapons
Ancient Super BallisticsI just watched this film, it is awesome, there is no real violence in it. They show a lot of neat weapons from a long time ago and talk about Rocket Arrow Launchers, Trebuchets, Polybolos, and a few others while also mentioning in passing a thing called the "Triple Crossbow".
Weapon MastersA sometimes ridiculously cheesy but still very helpful/educational show where two guys explore a given weapon each show, one goes and learns about it, how it was made, how it was used, etc, while the other tries to make a modern version that is as good or better.
*has some minor swear words, but not a lot.

History
Rome: Rise and Fall of an EmpireExplores and reenacts different major events in the history of the Roman Empire such as the rebellion Sparticus started (my favorite one so far)!
Has quite a lot of blood and vivid portrayals of battle, including blood spilling from mouth, some extremely painful to imagine ways of being killed (if you think about it, like I sometimes do), etc, so caution advised. Probably not quite the amount of gore in some movies, but definitely not an E rating film.
Last Stand of the 300: The Legendary Battle at ThermopylaeThis is an awesome (and as accurate as possible as far as I could tell) portrayal of the battle at Thermopylae, it is really an exciting re-enactment and shows the use of some interesting military tactics, I think it inspires me in that way as well as inspiring a few character types (the king of the spartans was pretty awesome in a few different ways).
There's definitely some blood in this one, though not as much as there is in some, but you hear squishing as they jab spears into the fallen to make sure they're dead, etc.

Warfare
Art of Wara DVD that explores the (at least alleged) history of Sun Tzu and how he put things into practice (assuming he existed) and also explores how the concepts in the book have been followed (or not) in real wars to achieve victory (or not, when they don't follow the advice in the book). For me it serves as a good motivation to read the book when I have time too!
There's some violence and some sort of photomanip-blood or something, while showing disconnected heads (again sort of photomanip) there may also be a bit of theater blood, but I don't remember anything horrible).

Exploration/research
In the Shadow of the Moon"One of the most inspiring documentaries I have seen in a long time. I literally caught the beginning on The History Channel right before going to bed. Next thing I know, I'm sitting on the floor mesmerized like a little kid until it ended.

In the Shadow of the Moon covers the beginning of Nasa and their journey to putting a man on the moon. It shows the stress, dedication, ingenuity, friendship and sacrifice these men, women, and families went through to achieve what I consider one of the greatest accomplishments of mankind. It is absolutely fascinating.

I think there's some minor language, but if you're looking for something inspirational, educational, and captures the excitement of exploration, then I highly recommend this documentary. It has a great soundtrack as well." - Roager
Planet EarthPlanet Earth gives a lot of inspiration. Lots of inspiration. It shows about various environments and creatures and plants that a writer would not otherwise know enough about to use in their books, if they even knew they existed. It is awesome. It is slightly environmentalist at times, and I believe it mentions evolution sometimes as well, however it is not too strong and not very subtle or immersive. It focuses on fact. Link - Rwebhu

I'll be adding to this, especially if people comment and say they're interested (don't wanna waste time doing this if no one is benefiting from it )

Good idea.

In the Shadow of the Moon

One of the most inspiring documentaries I have seen in a long time. I literally caught the beginning on The History Channel right before going to bed. Next thing I know, I'm sitting on the floor mesmerized like a little kid until it ended.

In the Shadow of the Moon covers the beginning of Nasa and their journey to putting a man on the moon. It shows the stress, dedication, ingenuity, friendship and sacrifice these men, women, and families went through to achieve what I consider one of the greatest accomplishments of mankind. It is absolutely fascinating.

I think there's some minor language, but if you're looking for something inspirational, educational, and captures the excitement of exploration, then I highly recommend this documentary. It has a great soundtrack as well.

Thank you! I'm hoping it works so I can have new ideas for things to watch... *cough* ahem, but of course the main purpose of this thread was to help others too.

Thanks Roager for that DVD suggestion! I put it into the main post, do you think I categorized it well? If you think it'd fit a different category better, I can change it.
*is looking forward to seeing In the Shadow of the Moon*

Yup, you categorized it right.

Good, thank you.

By the way, I'm going to add Art of War, a DVD that explores the (at least alleged) history of Sun Tzu and how he put things into practice (assuming he existed) and also explores how the concepts in the book have been followed (or not) in real wars to achieve victory (or not, when they don't follow the advice in the book). For me it serves as a good motivation to read the book when I have time too!
There's some violence and some sort of photomanip-blood or something, while showing disconnected heads (again sort of photomanip) there may also be a bit of theater blood, but I don't remember anything horrible).

Here's another one.

Last Stand of the 300: The Legendary Battle at Thermopylae
This is an awesome (and as accurate as possible as far as I could tell) portrayal of the battle at Thermopylae, it is really an exciting re-enactment and shows the use of some interesting military tactics, I think it inspires me in that way as well as inspiring a few character types (the king of the spartans was pretty awesome in a few different ways).
There's definitely some blood in this one, though not as much as there is in some, but you hear squishing as they jab spears into the fallen to make sure they're dead, etc.

Here's one about siege weapons and rocket propelled arrows among others! Ancient Super Ballistics
I just watched this film, it is awesome, there is no real violence in it. They show a lot of neat weapons from a long time ago and talk about Rocket Arrow Launchers, Trebuchets, Polybolos, and a few others while also mentioning in passing a thing called the "Triple Crossbow".

Planet Earth gives a lot of inspiration. Lots of inspiration. It shows about various environments and creatures and plants that a writer would not otherwise know enough about to use in their books, if they even knew they existed. It is awesome. It is slightly environmentalist at times, and I believe it mentions evolution sometimes as well, however it is not too strong and not very subtle or immersive. It focuses on fact. Link

Awesome, Juliet. That sounds absolutely amazing. *must see these* And it sounds like I could watch it with my little bro. Thank you for the contribution!

*should pay more attention to this and add more stuff to it himself*