What exactly are bedbugs and how do you know if you have them?

Bedbugs are bloodsuckers that feed mostly on humans. It's a myth that they are too small to see. In fact they look like apple seeds or lentils. The first sign that you have a problem is that you will wake up to find itchy welts on your skin, frequently in groups of three -- one each to indicate your guest's breakfast, lunch, and dinner. You might also spot pepper flake-like particles that are bedbug 'droppings'. 

Where are bedbugs usually found?

Bedbugs are most commonly found in and around your bed: your mattress, where the box spring and mattress connect, and in the dust ruffle that circles the bottom of your bed. But they can also be found in the walls, base boards, in picture frames, outlets, and other pieces of furniture.

Are bedbugs attracted to the fibers or the material used to make mattresses?

No. These night feeders are attracted to carbon dioxide, which we expel with every breath. 

Are bedbugs attracted to dirty people?

No. Bedbugs are equal opportunity biters -- they'll go after a host who is dirty or clean. 

Can a person prevent them by keeping a clean place?

No. Bedbugs can be found in budget motels as well as five-star resorts.  But it is easier to get rid of them if you reduce clutter. That way, they have fewer places to hide when the pest eliminator shows up. 

If caught early, could one take steps to prevent them from multiplying? [Such as] vacuuming, throwing away items they may have laid their eggs in, and putting all your personal items (such as books and pictures) in a freezer?

No. Although you may be able to spot and kill a few, that doesn't get at the root problem, which is the infestation itself. Professionals consider bedbugs the single most difficult pest to eliminate.

Are there any diseases associated with bedbugs or are they just an annoyance?

The good news is that bedbugs do not transmit diseases. However they can keep you from getting a good night's sleep, which, over time, is bad for your health.  Anxiety is not an uncommon consequence of sharing your bed with loads of bugs. 

Do bedbugs cause any disease apart from anemia?

Again, bedbugs do not spread disease, and there is little evidence that they can cause anemia, a blood disorder in which you don't have enough red blood cells to carry the oxygen required by your body.

Does getting a plastic cover for your mattress help?

A plastic cover will keep bedbugs out of your mattress (or trap them inside if they are already there), however, bedbugs hide in all sorts of places, and there's no piece of plastic that can cover everything. 

Ants and moths tend to dislike cinnamon and orange oil. Do bedbugs have any aversions?

No. The anti-pest industry is always testing new products, but they haven't come up with anything yet. 

How can one protect oneself at a hotel or hospital or other location.

Be vigilant. If you are in a hotel, check the bed before you go to sleep. And when you return home, wash everything in hot water. Bedbugs can't survive temperatures above 113 degrees Fahrenheit. As for hospitals, they are not necessarily bedbug-free zones.

If our home is now free of the bedbugs, how could they get into our bed in the first place? Do they come with us or things we brought from outside?

They could have hitched a ride on your coworker, the person sitting next to you on the train, or have hidden in that secondhand sofa you just bought.

Once the apartment is fumigated and everything is washed, sealed in plastic bags, what else can I do to prevent them from coming back? How do I make sure that any eggs that were not killed by the exterminator that hatch are killed before they can reproduce and re-infect?

Other than being cautious about what you bring into the house, there's not much that you can do. Most pest professionals will schedule more than one treatment in order to be as thorough as possible, so hopefully those eggs you are worried about won't hatch. 

What is the best way to rid these creatures?

Call a professional exterminator. 

How to get rid of them in the quickest possible time and the easiest way possible?

Getting rid of bedbugs is neither quick nor easy. The best way to get rid of them is by working with a professional. Expect to do a tremendous amount of laundry and sealing things in bags prior to treatment.