The intifada was a partially spontaneous phenomenon; after it began, the PLO attempted to claim that it had organized it, but historians view this as an after-the-fact attempt to assert more control than it really had.
In the months leading up to the first intifada numerous events occurred that increased the hostility between Palestinians and Israelis. On October 1, 1987 Israeli military ambushed and killed seven men from Gaza believed to be members of the Jihad. Several days later an Israeli settler shot a Palestinian schoolgirl in the back. Daily, the riots escalated throughout the occupated territories and where particularly severe in the Gaza Strip.
Under these already heated circumstances, incorrect rumors easily spread. The mere presence of stories, reinforced by the real incidents above, caused wild panic and street fights against Israeli policemen and soldiers. It is well documented that the combined effect of these events constituted the proximal spark of the first intifada. Howver, the general underlying cause of the intifada can be seen in the many years of military control that the Palestinians suffered under the Israelis.
Arabs maintain that the Intifada was a protest of Israel's brutal repression which included extra-judicial killings, mass detentions, house demolitions, indiscriminate torture, deportations, and so on. There is very little doubt that these did take place.
In addition to the political and national sentiment, further causes to the Intifada can be seen in the Egyptian withdrawal from their claims to the Gaza Strip (as well as the Jordanian monarchy growing weary of supporting Jordanian claims to the West Bank), the increasing density of population (caused by both the traditional rapid rates of birth in poor areas and the limited allocation of land to new building or agriculture under the Israeli rule) and the growing unemployment (in particular, the income from jobs in Israel allowed Palestinians to provide university education for their children - but there were few available jobs for the graduates afterwards).
Others point out that Palestinians felt abandoned by their Arab allies, the PLO had failed to destroy Israel and establish a Palestinian state in its stead as promised. However, it did manage to block the Israeli attempts to call for an election inside the territories (beginning with 1974), and as it seemed to many of them, they would spend the rest of their lives as second class citizens, without full political rights.
Considering all of the above and the mass scale of the uprising, it is of little doubt that it was not initiated by any single man or organization. However, the PLO was very quick to take matters into its hands, sponsoring riot provocateurs and enhancing their presence in the territories (called the "tandhim", or "organization") that was to guarantee the continuation of riots. The PLO was not uncontested, however, competing in its activities for the first time with radical Islamic organizations - Hamas and Palestinian Islamic Jihad, which also had a share in inducing further violence.
Much of the intifada was low-tech; dozens of Palestinian teenagers would ambush small patrols of Israeli soldiers, showering them with large rocks, attempting to kill with brute force and vastly superior numbers. However, this tactic soon gave way to using thousands of Molotov cocktail attacks, over 100 hand grenade attacks and more than 500 attacks with guns or explosives.
In 1988, middle-class Christian merchants initiated a nonviolent movement (or as some analysts hold it, were forced by the PLO) to withhold taxes - the legality of which under international law is disputed - collected and used by Israel to pay for the administration of territories. When time in prison didn't stop the activists, Israel crushed the boycott by imposing heavy fines while seizing and disposing of the equipment, furnishings, and goods from local stores, factories, and even homes.
Ultimately, Israel was successful in containing the Intifada. As the Palestinians were inferior in relation to the well equipped and trained Israel Defense Forces, and were generally unarmed. However, the Intifada pinpointed numerous problems with the IDF's conduct in the operative and tactical fields, as well as the general problem of Israel's prolonged control of the Palestinian territories. These problems were noticed and widely criticized, both in international forums (in particular, when humanitarian questions were at stake), but also in Israel's own public, in which the Intifada had caused a split. Some say it was the Intifada that caused the repeated rise of the Israeli peace movement (see Peace Now), and Yitzhak Rabin's eventual re-election in 1992. The Intifada definitely stopped only with the 1993 Oslo accords.