I am working on a paper describing the institution of the Dalai Lama and happen to be rereading Donald Lopez's great book, "Prisoners of Shangri-La: Tibetan Buddhism and the West." It is a brilliant mix of scholarship and readability; a must for anyone interested in Tibetan Buddhism, particularly our very strange Western ideas of what it 'really' is. A fascinating exercise might be to write yourself a brief essay on what you think Tibetan Buddhism "really" is (all about), cover topics including the Dalai Lama, the relationship to Indian, Chinese, and other geographic types of Buddhism, the saying 'Om Mane Padme Hum", and the likenesses (if any) between Tibetan Buddhism and forms of Christianity.
Likely, your views on each of these will be interestingly and surprisingly covered in Lopez's book. The book doesn't add much in the way of new scholarship on Tibet, but instead breaks down many of the misconceptions of Tibetan Buddhism, ranging from "demonic plagiarism" of Christianity (p.27) to (Tibet itself being) a "...peaceful, colorful, cheerful realm of pleasant and meaningful living" (p.7).
As with most things, the truth lies in neither the extremes nor some fabricated middle; but instead in the particularities realized under close examination. A few facts (without citation):
Buddhism was first (officially) introduced into Tibet in the 7th Century under King Songtsen Gampo.
Officially supported Buddhism collapsed with the reign of King gLang Darma, around 841CE.
Buddhism is reintroduced by Atisha (A Bengali who had traveled to Sumatra, Indonesia for teachings and had ascended to the higher ranks of an Indian Buddhist Monastery) in 1041. Schools focussing on his work and those of the teachers listed next would be called the 'new schools' in opposition to the 'old school' Nyingmapa (ancient ones).
Tilopa, Naropa, Marpa, Milarespa, Gampopa all are active in the 11th-12th centuries, transmitting Indian Buddhist ideas into Tibet. Each is the disciple of the prior in this order. Gampopa would go on to form the Kagyudpa school.
Tsongkhapa develops strict new school of Buddhism in the early 15th Century, the Kadampas, later to be called the Geluks (Virtuous Ones).
The First Dalai Lama was the Third Dalai Lama. Doesn't really make sense (like many things), but it goes like this: the 'first' Dalai Lama was Sonam Gyatso, a Geluk monk who visited the Mongol leader Altan Khan in 1578. Altan Khan bestowed him the title 'Dalai', which means 'Oceanic', referring to the wisdom of the person it is bestowed upon. 'Lama' basically just means teacher, or great teacher.
Sonam Gyatso, however had been recognized as the reincarnation of a prior lama, and he in turn the reincarnation of another lama (this one a disciple of Tsongkhapa). So the first (temporally) of these (the student of Tsongkhapa) was posthumously given the title, the First Dalai Lama. And the rest is history, so to speak.
Tibet has never been in much of a state of political peace, as one might assume. They've almost always been threatened, under attack, or occupied by either Mongolia or China (Britain also once in 1903-4). Tibet also had a heroic/warlike period in the early 8th century when it actually conquered China all the way to Beijing.
Tibet has also never been unified in any clear way. Under the Dalai Lamas, especially the 5th and 13th, there were efforts with some success to reign in the distant and opposing tribes/polities of Tibet, but for the most part, 'direct' political power has been restricted to a valley around Lhasa, with extension to Shigatse in the East. It has only been with the 1959 uprising and suppression by the Chinese that a greater (if not more urgent) cry for Tibetan Unity has been raised, and even this is not a priority for many Tibetans. None of this should go to deny the fact that the Chinese occupation has been tantamount to genocide and every effort should be made for its end.
Well... Get Lopez's book if you're interested in more, and I always recommend Geoffrey Samuel's "Civilized Shamans" if you want an extremely thorough, though readable, coverage of the entirety of Tibetan Buddhism/Civilization from a mostly anthropological point of view (analyzing most periods in terms of 'cultural patterns' which I found very helpful). For a less scholarly, though thorough and extremely useful, coverage, see John Powers' "Introduction to Tibetan Buddhism." Lopez's book has the virtue of being great for all readers; Samuel's I would only recommend to those sincerely interested in the intricacies of Tibet and its various forms of religion/culture, and Powers' is great for all but the more advanced students. Oh... and I just read a short paperback by the Dalai Lama, edited by Jose Ignacio Cabezon (one of the current giants in the field) called "Answers: Discussions with Western Buddhists" which is extremely useful in getting a feel for a broad variety of issues in contemporary Buddhism from the Dalai Lama's perspective.
Good luck... Remember to smile. I remember an interview with comedian/actor Steve Martin in which he was asked how he managed to remain funny for so long and he said he usually dedicates 5-10 minutes each day to just smiling at a mirror. Geshe Michael Roach has also remarked, in his teachings on yoga, that smiling loosens knots in the two channels around the face, allowing pranna, ethereal energy (inner wind or subtle energy), to flow more smoothly throughout the body. Whether either of these are actually going to work in anyone else's life, who's to say? But if they work for you, good! There's reason to smile. If they don't and you think these guys are just crack-pots, then hey, at least you're not a crack-pot too (right?). And there is a good reason to smile!
Speaking of crack-pots, I'd better get some sleep before I somehow become one myself. Best, jw