Since this will be relevant to my comic and different people have different takes on these creatures, I thought I'd write this educational journal about how vampires and werewolves (alternately called weres or lycanthropes, especially if they are not wolves) are done in my world/universe/continuum/whatever.

Several but not all of these facts will be mentioned during my comic, so if you're curious, here's a primer of sorts on them for those of you that like to read about stuff.

VAMPIRES
In this world, vampires are like a plague, feared by many for their dangerous nature. They are such a threat that a special division of the police force in most cities (known as Vampire Slayers, or sometimes simply Slayers) are specially trained to fight them. Supellex City gets the most vampire activity, due to its large population, often overcast weather and a great number of dilapidated areas for vampires to take shelter in. It is rumoured that the Queen of Vampires hides somewhere within this city, and it is here that the story takes place.
Creation: No one knows where the first vampire came from, but they do know how they create more. It usually takes careful planning, since in order to become a vampire, someone must have every last drop of blood drained from their body. Even if someone is killed by a vampire, they will remain dead if any blood remains in their veins. Thus, while people are often killed by vampire attacks, they do not rise if the vampires could not take all of their blood in one go. Conversely, a vampire may just 'snack' on someone to keep them alive for later. Vampires cannot reproduce conventionally.
Undeath and Blood: Vampires are undead. By all clinical standards, they should be dead--no vital signs, etc--but some form of unholy magic keeps their soul with their body and causes them to stay animate. They do not age and are immortal. As a strange effect of this condition, they do not cast a reflection in a mirror, though they do cast a shadow if exposed to light. Because of how they are created, vampires do not have blood, and they do not bleed. The blood they obtain from others apparently never makes its way into their veins, either.
Physical Changes: Vampires look very much like living people, with a few exceptions. Though their skin is not always visible beneath their fur, it will take on a paler tone. They will always have large, sharp fangs, which is more conspicuous on some species than others, and their claws may be slightly larger and sharper as well. In many cases, vampires are not easily identified on sight, which is advantageous to them.
Diet/Hemophages: Despite being clinically dead, vampires seem to require nourishment to fuel their existence. They obtain this energy from blood, with fresh blood from living people being much more nutritious and desirable. It is unknown exactly how they metabolise this without a working bloodstream, but they definitely have some form of digestive system that only knows what to do with blood. Just like living people, they are able to feel hungry, and they will waste away and eventually starve to death in complete absence of blood. Conversely, a very well-fed vampire can actually gain fat and/or muscle. They seem to be retain the same metabolism they had in life, thus some vampires require more blood than others.
Vampires as Predators: The fangs of a vampire are to aid them in obtaining blood, the preferable method being the trademark bite to the neck. All of their senses (especially sense of smell) are greatly enhanced, and they are even able to hone in on the sound of a heartbeat from quite a distance away. They have very strong hunting instincts and cannot help but see the living as food, even if they obtain blood from other sources, so most people consider them irredeemable and untrustworthy.
Powers and Weaknesses: In addition to their enhanced senses (including amazing night vision), vampires are typically stronger than a living person, with their strength directly proportional to age, muscle mass, and how many vampires they have created. They use either fresh blood or reserves of blood to regenerate from any injuries (with the unusual exception of the scars from when they were bitten, which remain forever). Fortunately, there are ways to kill them. The most foolproof ways are a stake through the heart or exposure to direct sunlight. Silver, crosses, holy water, and bright light can all greatly harm them, but they can eventually regenerate. Garlic is very effective as a vampire deterrent, as they seem to have a powerful allergy to it, but it doesn't seem to otherwise harm them. They also cannot enter someone's home unless they are invited in by someone that lives there.

WEREWOLVES
Werewolves are considered a much lesser threat than vampires due to their heightened control over their condition, and some are even employed by the police force to help fight vampires. They are strongly encouraged to learn more about their condition and how to control it, and many are quite successful at this through methods such as meditation. Nevertheless, police are still trained to learn how to handle out of control werewolves, because some simply cannot control their rage.
Origin: The original werewolf was (as the name suggests) a wolf. No one knows precisely how old they are, but it is speculated that the condition arose as a spontaneous magical mutation. It is a dominant trait and is passed down to anyone with werewolf in their lineage. Wolves and dogs are most commonly seen with this condition, though with the increasing open-mindedness concerning inter-species relationships, some other unrelated animals may have this condition due to being part werewolf.
Transformation: Regardless of species, all werewolves have only two forms, their normal form and their 'wereform'. The wereform is essentially an enormous quadrupedal version of their regular self with elongated fangs and claws, even on species that do not normally have these attributes. In this form, they become much stronger but much more primal in intelligence--a semi-sentient predator. They can only take on this form at night. They involuntarily transform on a full moon, but all other nights they can transform back and forth at will (although they may lose control and transform anyway if they are angry).
Powers and Weaknesses: Despite having some supernatural/magical qualities, werewolves are mortals. They age normally and eventually die of old age, though their lifespan is just slightly longer than that of non-werewolves. They have a 'sixth sense' for other supernatural beings (such as ghosts, vampires, other werewolves, etc.). They are immune to being made into vampires. Any vampire to attempt this anyway would be quite disappointed, as their blood is neither nutritious nor tasty to vampires.
In Normal Form: They have a slightly heightened sense of smell and hearing compared to normal. They can be killed in all of the same manners as anyone else, though quick thinking and a shift into their wereform at nighttime may save their life due to...
In Wereform: They regenerate amazingly fast. It is extremely difficult to kill them. The exception to this rule is silver--wounds caused by silver weapons will heal at a normal speed, thus they can indeed be killed by a silver bullet as the popular legend states. They also cannot regenerate lost limbs, so decapitation is another (albeit more gruesome) way to kill them. In this form, they also have extremely keen senses of smell and hearing and overwhelming physical strength, though they may be difficult to communicate with due to their lowered intelligence.