I suggest that people take a look at some absinthe enthusiast sites to better acquaint themselves with the subject. La Fee Verte would be a good one to start with. There are a lot of so-called absinthes stemming primarily from Eastern Europe that are absinthe in name only. Real absinthe is made in small batch stills (one distillery that produces the excellent "Jade" line of absinthes actually uses stills that were used by Pernod Fils when it made authentic absinthe before the ban) using fresh herbs. The herbs (wormwood, angelica, fennel, green and/or star anise, among others) are macerated in a strong wine base before distilling. Most so-called absinthes have dried herbs macerated in an alcohol base after the alcohol has been distilled. Many use petite wormwood, which is not the right thing, and tons of star anise, which overwhelms the flavour of the drink with the kind of strong licorice flavour that you get in pastis. This is not what real absinthe should taste like. Neither should it be overpoweringly bitter or at all medicinal in taste - a sure sign that what you are drinking isn't the real deal. Absinthes come in two main varieties -- green (most common in French absinthes) and white (more common in Swiss ones). Most of the best absinthes come from France or Switzerland, although there are worthy ones made in several countries.
Real absinthe can be wonderful but I have never had a Czech absinthe that tasted remotely like the real thing. One should never, ever burn the sugar cube as part of the drinking ritual. A good absinthe is made by pouring about an ounce into a glass (better if you have a real absinthe glass). Water is added in a very slow trickle over a sugar cube (although many absinthes don't require the sugar added). The key thing is to very slowly add the water and watch the process of the absinthe beginning to louche as the oils of the herbs interact with the ice cold water. In the best absinthes, there is a dance of haziness around the added water, until eventually the entire drink goes cloudy. Usually the drink is mixed at 1 part of absinth to 3 or 4 parts of water. If you go to YouTube, you can see some pre-ban absinthes louching, and it is pretty cool.
Absinthe was banned in most countries around WWI because it was thought to cause madness. The chemical thujone in wormwood was blamed. But there is less thujone in a bottle of absinthe than there is in chicken seasoned with sage -- sage has lots of thujone in it. The reason that people went mad drinking absinthe is that it is normally bottled at 140-170 proof. Taken in moderation and diluted with cold water, it is a wonderful drink, with the best examples having a complex and intriguing flavour. I have a particular fondness for La Balance, Jade 1910, Jade Edouarde, Doub's Mystique and, for a budget price, the Canadian-made Taboo Gold (which doesn't need sugar added, but does have a kind of Juicy Fruit overtone to the classical absinthe taste). Marilyn Manson's own brand is passable as well. I'd recommend the latter two for a novice interested in trying to get some decent quality absinthe at a good price, but the others I mentioned are much better.
As for mixed drinks with absinthe, you might want to try Toulouse-Lautrec's favourite drink, which he called "Tremblement de terre". It means "earthquake". One part absinthe, one part brandy. I suggest that you sit down before ingesting it though.