Designing weapons and armour
Often one sees that someone draws these things looking all silly. Slight exaggeration of weaponry and such is of course fine in a fantasy setting, but it's not uncommon at all to go over the board and draw something that couldn't function in reality at all. This mostly applies to portraits and other realistic imagery, not really unit graphics as such.
Now, my point is simply: you can make weapons and armour be flashy and cool while keeping them very realistic, and a real-world reference also helps you to get things functional without having to think what kind of sword handle would work and what wouldn't, for example (and, no offense to artists drawing fantasy stuff, but that usually goes a bit awry), and that there are plenty of references available. So even if you don't feel the need for the weapons you draw to look realistic, having some references still helps to actually make it look good (in the same way as having a reference when drawing a person makes it much easier to get it look right and good).
For this purpose, I thought I'd go through some related sites I know of and post some links here. These are armouries, general information/review sites, etc, which contain good pictures of historical arms and armour. Mostly (if not all) are only european stuff though (which sort of fits with at least the mainline Wesnoth setting), but that's all I had available right now.
- http://www.armouronline.com/ - the full body armour section is good, weapons are generally crappy here.
- http://www.myarmoury.com/ - hard to navigate, but contains a lot of good pictures, if you take the time to find them. The "reviews" page is a good place to start from.
- http://www.lutel.eu - quite a number of all sorts of weapons in the catalog (especially the polearms and such look nice).
- http://www.darksword-armory.com/ - a collection of often historically accurate weaponry
- http://www.by-the-sword.com/ - various things
- http://www.siue.edu/COSTUMES/history.html - a site with lot of pictures of clothing from different eras and areas, from 19 century engravings. The scans could be of higher quality, but you can find plenty of stuff for reference/inspiration for fantasy clothing. Many of the same pictures can also be found in a book A Pictorial History of Costume (Pepin Press, no author).
Feel free to post your additions (especially to the type of items not covered on these sites), too, since we don't have much here yet.