What is Meat Smoking?

Meat smoking is the process of surrounding a piece of meat in a moist and smokey chamber while cooking it low and slow. The prolonged exposure to wood smoke allows the meat to absorb much of the flavor, giving it a tasted that can't be matched any other way. Meat smokers generally shoot for a temperature range between 200º-225º, depending on the type of meat you are smoking. Also, according to Wikipedia, smoking meat also assist in preserving meats. "There are two mechanisms for this preservation: dehydration and the antibacterial properties of absorbed smoke." Also see Wikipedia's general smoking page for more information.

Does it cook the meat, or just add smoked flavor to already cooked meat?

The smoke itself does not cook the meat. This was a misunderstanding of mine as I was first getting into meat smoking. The heat of the fire or heating element are what actually cook the meat.

Is it safe to eat all the time, or is there a health risk to regular consumption?

This is a tricky one. Anything smoked or cured you buy at the grocery store contains nitrates as a preservative, and if the label says 'smoked', it is typically done with chemicals (like liquid smoke). By smoking meats at home, you eliminate the need for all of these preservatives. The same goes for most foods you cook at home when compared versus any pre-made food. Other than undercooked meat (not reaching the appropriate internal temperature), and the concerns about preservatives that aren't present in home smoked meat, I have read no heath concerns for eating smoked meat. Eating too much meat in any form can be problematic of course, but that is a completely different issue.

How long does it take to smoke meat?

The time it takes to smoke meat varies greatly based on the cut of meat, its size, and how done you want it. I've smoked a rib eye roast in about 4 hours, and have smoked a pork butt in 22. Both came out amazing. One phrase that has stuck with me (and proven true), is that when smoking, "its done when its done". This chart is a great resource to estimate how long things will take. I reference this chart every time I switch from one type of meat to another, or if I am planning for company. It is worth bookmarking. You'll also find that your setup will yield a certain set of results. Start with the chart as a guide, but begin building your own list of times based on your experiences with your equipment coupled with your preferences.

What is different between old school meat smoking and modern meat smoking?

Historically, meat smoking was used as a preservation technique. Refrigeration and the easy access to meat in our culture have made meat smoking less about necessity, and more about taste. 

Can I smoke things other than meat?

You sure can. I've successfully smoked potatoes, and plan to smoke corn in the near future, but you can smoke just about any vegetable. With a few modifications, you can cold smoke using your smoker as well. That opens up cheeses, salts, and nuts.