Owning a number of swords myself for a variety of uses, I think I can offer advice on this...
If you are looking for a sword for ritual use, first off, you don't really need it unless you're in a coven, usually working outdoors. The Athame serves that purpose. Very rarely will you see a coven with more than a single sword.
If you are looking for a sword for combat, reenactment, or self defense, basic maintainence is to carefully wipe down the blade to clean it, and then apply a thin coat of oil using a woolen sponge. (Felted wool) Then, oil the handle if leather or wood- I prefer linseed oil for this and a mineral oil for the blade. The oil should be renewed weekly.
I can also offer advice on swords depending on your specific use, although in general I recommend Albion Swords, they're one of my favorite makers and they only produce very high quality stuff.
http://www.albion-swords.com/ They don't really produce asian weaponry styles, however, and I'm not really familiar enough with the manufacturers to offer advice on that.
As for Hemorana claiming that swords are slow... Er, no. We commonly portray swordfights as VERY slow but even a claymore can be an extremely quick weapon. Take a look at modern fencing at the olympic level- thats an accurate representation of how fast sword fights were. Swords do NOT weigh much! My heaviest sword weighs 12 pounds and most of that is because I'm particular about how I like them balanced. It's also a 5 foot long claymore.
Also, remember that it was most common for a swordsman to fight in some form of armor (not usually cap-a-pie until the later centuries) and a shield, providing a lot of defense against an axe or hammer. A sword also has a longer reach- because the point is shar, it can be used in a full lunge, not just as a slashing weapon. Almost all of the successful sword types (especially the scottish back-sword) were of a thrusting type, and the most successful sword at all, the roman Gladius, was a purely stabbing weapon.
Very rarely would you see a 'battleaxe' on a battlefield in Medieval Europe, and even rarer would you see a hammer, especially by the base combat troops, the militias or levy. Most common was a simple spear- similar to a boar-spear used for hunting, called a pike. This is the -only- weapon that is effective against a cavalry charge, preferably backed by a bunch of archers. You would also see glaives, halbers, or other polearms where one would expect to be fighting against cavalry. Mounted combat usually used lances- sharpened, edged lances against other cavalry, but a long sword is extremely effective from horseback- this is where we get the saber and was a key use of the scottish backsword. Archers were another common troop type- while they need to be protected, an archery regiment could put hundreds of thousands of arrows downrange during the course of a battle, and even a 50 pound draw can punch through most armor if it hits correctly. It is easily possible for even an inexperienced archer to put 5 arrows per minute down range, over the course of an hour this is 300 arrows per archer per hour. For a group of 50 archers, thats 15000 arrows per hour. And those are low estimates- thats about 1 arrow every 12 seconds. Given enough archers and a long enough charge, it IS possible for archers alone to turn back a cavalry charge, however, it's like stopping an avalanche with a fire hose.
The primary reason the 'battle axe' and 'battle hammer' were not used is because of reach- they in general lack a point, so they have to be used as slashing weapons. They are also end heavy, causing a fighter to get exhausted quickly. Finally, they are not condusive to shielded combat. Simply put, two trained fighters, one using a backsword, one using an axe, the swordsman would win. The primary reasons swords were not used in the levy is because they are hard to learn to use. The romans solved this with their gladius- because it's a stabbing weapon, and because they faught in a phalanx, individual experience is subsumed by discipline.
I suppose I rambled a bit, but I really like this topic and I've done a lot of research, and claims that 'swords weren't really used' annoys me. The article on Medieval Warfare on Wikipedia has a ton of really good information in it, as well as links and sources which provide more. You can find it here:
http://en.wikipedia.org/wiki/Medieval_warfareEdit: We do see 'leaded hammers', closer in form toa club, being used by the lightly armored english longbowmen, however, they were used in this case almost exclusively, and many longbowmen carried swords instead of the hammer.