I've been working on this for my own campaign. The setting is the English Anarchy of 1135.
Swords: Typically only One-handed swords of about 30 to 36 inches, corresponding with
Oakeshott Typologies X,
XI, and some
XII. Some type XII's were two-handed, but really didn't start appearing until the late 1100's. Terms like
longsword, and
bastard sword were not in use yet...they were just called
swords.
Also under swords, were
Falchions. These were used by both common soldiers and noble knights. It was a utilitarian weapon that may have actually seen more use in war than typical knightly swords - though it's debated. There are very few surviving examples which likely means they were either very common but used to destruction, or not very common.
In the Middle East and Northern Africa, Scimitars were the weapon of choice (slim, curved, single-bladed weapons, not the uselessly impractical things D&D calls "Great Scimitars" - which were almost exclusively ceremonial only).
In Japan, the precursor of the Katana was the sword of the day, called a
tachi. It was slightly longer than the eventual Katana (or Uchigatana - from the late 1100's), and had more of a curve. It was worn edge down (unlike the Katana, which was edge up to facilitate a faster draw), and was mostly a cavalry weapon. The metal folding techniques of forging had already come into practice by this time, but the Tachi was still a more fragile weapon than the latter Katana, and was not as well suited to one-on-one sword fights/duels as the Katana was. The Daisho (Wakizashi and Katana combination) was not in use yet. There were however, tachi that deviated from the standard length. Some could even be as short as the later Wakizashi and were called
Kodachi.
In China, most swords were straight and single or double edged (like the sword from
Crouching Tiger, Hidden Dragon).
Throughout the rest of Asia (like India) swords could be a mix of straight and curved type swords. They all had unique names, and slightly unique characteristics, but D&D stat-wise would be similar or exactly the same as scimitars, tachi, chinese swords, etc.
Knives: Typically single edged of the
Saex variety. They could be of the common small size (anywhere from 6 to 10 inches), up to larger almost sword or cleaver like weapons. The double-edged daggers and dirks hadn't really come into common existence yet. They were more from the Late Medieval and Renaissance (13th Century on).
Bows: In the 1100's, Longbows had not really come into use by the English or any other Europeans except the Welsh. The Welsh Longbow could be as tall as a man, but was a very rough made bow (not like the well worked yew bows of the English in the 13th Century on).
Longbows were also quite different from the "Warbows" of Agincourt. Warbows could have a draw weight of 120-200 lbs., and required very specialized archers that had trained with them all of their lives (extremely developed upper-body musculature and even altered rib-cages). The Longbow of the 1100's would have had a more normal draw weight range, likely anywhere from 50-100 lbs.
Along with Longbows were standard bows of varying lengths, used mostly for hunting, but also used for war. Though massed archery had not really become a prominent part of European warfare yet.
Composite Bows were an Asian and Middle Eastern weapon only. The weather conditions (humidity, rain, etc.) in Europe (especially in England), would have caused the glues used for the composite parts of the bows to come undone, and resulting in the bow being ruined. Composite bows could have ranges equaling or even exceeding the later European Warbows, and could have comparable damage (less draw weight though relatively equal arrow velocity, but composite bow arrows were likely lighter and shorter than Warbow arrows).
Armor: Mail (not chainmail) was the most coveted form of armor througout the world. Mail was used by almost every culture on the known world - wether European, Middle Eastern, or Asian.
Studded Leather did not ever exist. it was likely a misinterpratation of 12th centure artwork depicting Brigandine-like armor.
I'm including the armor section of my houserules. Ignore the rules that are in the section, and the defense ratings on the table. It's not all fully worked out yet and is still much a work in progress. However, the armor descriptions and pictures should be of use to you. The Armor in this document is also almost exclusively European. I haven't gotten to Eastern Europe, the Middle East, or Asia yet.