While you can study about Shamanism and use some of its techniques, unfortunately that won't make you a Shaman. Shamanism is the practice of Animism for a tribe who are Animists, who have accepted you as a conductor of the spirits - it's a full time Profession that's for a community, usually indigenous, and it means you have to be accepted as a student of a practicing Shaman, and be nothing else!
Shamanism is the personal experience with the spirits, and a Shaman is the mediator between the self and the divine - which is everything. The Shamanic techniques were developed to alleviate Spiritual Emergencies within a clan or someone's life. When these emergencies happen to someone destined to become one's life, there is often a death and rebirth experience. Shamans are often healers, and the seek out help in the other world by often ancient trance techniques and bring back answers to a patient or a community. To bring back these answers they may spiritually travel to the lower or the upper world, into the past or the future and other odd spaces. They exorcize harmful influences they believe cause disease. The spiritual disease that allowed the viruses and germs to gain a beachhead in one's body to begin with. These techniques are not exclusively Native American, or Siberian -- they've been known for several millennia by most of the Peoples of the World - part of the spiritual technology most religions and cultures share - including most of Pre-Christian European cultures. Most of these techniques aren't dangerous, are very easy to use, and they work just as well as some of the more extreme techniques, such as taking certain drugs.
The old Druid technique for creating a true Bard, for instance, amounts to sensory deprivation for weeks at a time in a dark cave; The old Druid technique for ecstatic trance involves being swaddled in a bull's hide and ingesting noxious substances -- there are better ways... With techniques that can either kill or cure you: 'youse pays yer dough and ya' takes yer chances' - desperation need not be that desperate anymore. These things are fascinating to read about, but like a tiger's beauty - it's best appreciated from a distance (hopefully with barbed wire enhanced concrete moats in between) Of course, "we" (those who have medical insurance) now have Medical Doctor and HMOs who glom most of the healing work that's done these days - "Can you say MONE-OP-POE-LEE, boys and girls..??"
The truth is, relatively few people, then or now, want to take the time to work with trance techniques, or take journeys to other less ordinary realms - the boss is on your case, the mortgage is due, the other bills pile up, and the Ordinary Grind of Mundanity slowly takes its toll. But the general grind of Mundanity, which is safe but often terribly boring, can't protect one from the Spiritual World forever -- it's better to have the knowledge to light a candle than to hide in the darkness.
In most non-Western places, Shamans are valued professionals, and though their work is subjective, it's probably more effective than psychoanalysis, psychology, and psychiatry -- and its results are surprisingly similar across the many cultures that still practice it.
$HAMani$m vs. Shamanism
Carlos Castaneda brought the mystique of Shamanism and Sorcery to the 60's counter culture; while Michael Harmer bought back some of the techniques of the Shamans he worked with in native cultures. Shamanism usually doesn't stand by itself, again, it's usually grounded in an Animist culture that supports it. That's why the New Age Movement's "SHAM-manism often rings false - it's more of a sham than not! The New Age habits of wrecking the cultures, and stealing the lifestyles, beliefs, and spirit to repackage them for trendy upscale wannabe buyers at outrageous prices; pretending to be an initiate of an "Native American" Tradition, then stealing their art, music and culture and copyrighting them as original works is something the New Age "culture" showd little or no shame over. "Missionary work", vandalism, and desecration of holy sites, and raping the Earth for crystals is just business as usual for the spiritual entrepreneur. The New Age Movement was/is infamous for "borrowing" the spiritual techniques of others, stripping them of their context so they can be mass merchandised as fads, novelties and entertainment for big bucks. The American version of Western Culture is decadent and sick, and it'll exploit anything and anyone if it can make a buck off of it. It's a shame that most of the New Age Movement was/is the same way. These Shamanic techniques aren't that hard to find, they're readily available - it only takes some research time! $ave paying the fancy $$$$$s and do it yourself!! And remember -- Caveat Emptor!
[[The New Age is all but defunct now But many of their ideas are still with us]]