Originally I was going to ask about medieval swords, the materials they were made out of, how they were made and design features (like the purpose of fullers), but I realised that it would be easier for everyone if I just did the research myself. On that note, is there any websites, books, documentaries or articles that you guys recommend where I can gain the knowledge I desire.
A good beginning point is an overview of the various types of Medieval swords. Recommendations for this tend to be heavily dependent on the works of Ewart Oakeshott, and my recommendation will follow this pattern:
Ewart Oakeshott, The Sword in the Age of Chivalry, Boydell Press, originally published in 1964, and still available courtesy of reprints.
Ewart Oakeshott, Records of the Medieval Sword, Boydell Press, 1991, and, as above, reprinted and still available.
Ian Peirce, Swords of the Viking Age, Boydell Press, 2002, and again, reprinted and available. Essentially the Viking Age prequel to Oakeshott's Records.
There are also online resources. For original Medieval swords, rather than replicas, the best online sources are museum websites, and my favourites for Medieval swords are the Met Museum and the Wallace Collection, since they have the combination of large collections and good websites provided plentiful data:
The Royal Armouries and the British Museum are also excellent.
The short answer to "materials they were made out of" is simply iron, iron and steel composites, and steel (not including the occasional use of copper alloys for guards and pommels, and organics for grips). The longer answer involves some serious metallurgy. There are two superb sources on this:
Williams provides substantial information on metallurgy and steel-making, but the focus is on metallurgical/metallographic examination of swords, along with what can be deduced about their manufacture from this. Note that much of this work has also been published in various papers by Williams, with many of these appearing in the open access journal Gladius: http://gladius.revistas.csic.es/index.php/gladius
Föll goes into immensely greater depth on metallurgy and the history of metals technology, and looks at swords much more broadly, covering Middle Eastern and Japanese swords. Together, Williams and Föll have provided complementary resources that will let you dive in to seek your answers.
Williams and Föll provide information about swordmaking, and Oakeshott's Records and Peirce have chapters on this, too. What isn't always obvious is what some of the processes discussed by them actually look like in practice. Video examples are very good for this. However, most video of the making of replica Medieval swords shows smiths starting with modern bar stock, pieces of steel with much of the work already done. Often, power tools are heavily used (e.g., with a power hammer replacing the 1 or two apprentices who would have been helping a historical Medieval swordsmith). It is very unusual today for swordsmiths to start with pieces of inhomogeneous bloomery iron/steel, and work from there, folding, forging, laminating, etc., and to do the work without modern machinery. However, this is still the modus operandi of Japanese swordsmiths, and their practice, e.g.:
serves as a convenient illustration of much of what a Medieval swordsmith would have done. Differences to note are that:
a Medieval European smith would often have started with iron/steel that had already been folded to get rid of most of the slag and to homogenise the iron/steel (e.g, https://www.youtube.com/watch?v=a-35jC8-4FI and following parts), rather than starts with chunks of the raw bloom straight from the smelting furnace,
European differential hardening was usually done by slack-quenching (interrupted quenching) rather than by a clay coating, and
especially in the later Medieval period, power tools (water-driven) such as hammers and grinding wheels might have been used, depending on the scale of the swordmaking workshop.
As for the design of swords, there is rather less in the way of comprehensive works. More-or-less scientific approaches to the design of swords date to the 19th century, with notable works being:
G. S. Marey-Monge, Memoir on Swords, John Weale, 1860: https://archive.org/details/MemoirSwords/
John Latham. "The Shape of Sword Blades." Journal of the Royal United Service Institution 6(4), 410-422 (1863): https://www.keithfarrell.net/research/transcriptions/1863-john-latham-shape-sword-blades/
A modern book that in many ways follows this old tradition is:
Unfortunately, a significant part of this literature is rather on the "less" side of that "more-or-less scientific", with "scientific" explanations used largely as rhetoric. Meaningful quantitative analysis of design is relatively rare. We do find some in modern work. For example, Föll (in chapter 12) discusses the design and the physics/engineering of swords, and
includes discussion of design and physics as well as swordsmithing. For a little taste of what Peter Johnsson has contributed, see https://www.peterjohnsson.com/the-making-of-a-long-sword/ where he writes about the design and making of a longsword, and Föll's use of this in his discussion.
One book that appears well-regarded that includes some discussion of design and science/engineering is
I haven't read this, and suggest it purely on the basis of the table of contents and favourable reviews.
Since you specifically mentioned fullers, I'll note that these are just one aspect of the cross-section of blades (see Latham (1863) for a good discussion of many aspects of the cross-section). Essentially, they provide less weight for a relatively small drop in stiffness, or, for a given weight, a thicker and stiffer blade. For an good online discussion of this, see
A superb online resource for the science of swords is Vincent Le Chevalier's
where, mixed in with articles on historical swords and data for them and historical martial arts are some excellent articles on various properties of swords. From a scientific viewpoint, perhaps the centrepiece is Vincent's Weapon Dynamics Computer, introduced in http://blog.subcaelo.net/ensis/documenting-dynamics-of-swords/
There are also a number or web forums with plenty of good technical discussion. Perhaps the most Medieval-focussed of them is
but there is also plenty of good material on
and even some on the close-to-home
Of course, the technical and design stuff is spread over various threads and posts, and can be hard to find, so it may well prove more productive to use the search functions rather than just browse. As with all sources like these, the reader must pay attention and judge the quality of the information rather than just accepting it all as true.