Welcome to the forum Mighty.
The question has of course been answered before, but the answers need to be repeated again and again since this is a leftist site and we hope to analyze past mistakes in order to avoid them in the future. The question has been answered in numerous ways, since among the Left there is of course a variety of viewpoints. I will give you my 'conservative Marxist-Leninist' opinion, and will note that I have spent countless hours on this topic which is of great personal importance to me, given that I was born in and spent part of my childhood in the USSR prior to its dissolution:
Gorbachev in my view was a political idealist whose dominant personal qualities were vanity and weakness of will. His idealism led him to believe in the social democratic alternative to socialism in politics and economics, and to abandoning the Soviet Union's allies all over the world in the interests of world peace, cooperation and inclusion of the USSR in 'the common European home'. His personal vanity and popularity in the countries of Europe and North America led him only to increase the tempo at which the USSR abandoned its Marxist-Leninist ideals and sought integration with the West. His personal weakness of will prevented him from decisively intervening in the hot spots of local civil war in various regions of the USSR in the late 1980s, and he listened to advisers and friends like Eduard Shevardnadze and Alexander Yakovlev who were outright counterrevolutionaries with pure hatred in their hearts not only for socialism but the USSR itself. Gorbachev was easily influenced by crowds of liberalized Muscovites portending to represent the whole country, he was sensitive to the opinions of liberal Soviet journalists and those of the West, and his main goal according to numerous personal accounts was to avoid repression and bloodshed. It is for this reason that in each vital instance that called for decisiveness, he cowered away from responsibility. The last instance of this was of course in December 1991, where he refused to arrest the three traitors meeting in Belovezhsk to formally break up the country. In the area of economics, Gorbachev and his team appeared entirely incompetent, based on the measures proposed and implemented. The laws on State Enterprises and Cooperatives in 1987 and 1988 were not thought through to conclusion, resulting in all sorts of economic irregularities and the legalization of black market speculators' money, and the decision to disassemble the planning mechanism in May 1988 created chaos that fed anti-socialist and nationalist separatist political groupings then being allowed to form.
Here are some materials on the subject which you might find interesting:
The first is an essay I wrote last year which discusses the concept of glasnost, and notes that the historical process of glasnost in the USSR must be separated from the concept of 'openness' in media and social life. It notes that in actuality the Gorbachev government effectually waged an information war against the old tenets of Soviet socialism, promoting first a liberal socialism and eventually full-on bourgeois democracy and market fundamentalism, as odd as that may sound:http://www.soviet-empire.com/ussr/viewtopic.php?f=110&t=52073
More threads from this site on the topic (obviously not exhaustive):http://www.soviet-empire.com/ussr/viewtopic.php?f=123&p=795790http://www.soviet-empire.com/ussr/viewtopic.php?f=123&t=51871http://www.soviet-empire.com/ussr/viewtopic.php?f=128&t=41537
A couple books and articles I'd recommend:http://www.amazon.com/Socialism-Betrayed-Behind-Collapse-Soviet/dp/071780738X
-> An excellent Marxist-Leninist analysis, albeit somewhat unvarnished in partshttp://www.amazon.ca/Revolution-Above-Demise-Soviet-System/dp/0415143179
-> A non-socialist analysis, although Kotz does seem to sympathize with some Soviet ideals, and does discuss some of the major errors of perestroika.http://www.amazon.com/Destruction-Soviet-Economic-System-Insiders/dp/0765602644
-> An excellent economic analysis which incorporates first hand accounts from managers on the ground who discuss how the planning system was ripped apart between 1987 and 1988 while a market system failed to form, causing economic chaos and subsequent social unrest.
Sam Marcy's analysis from the time:http://www.workers.org/marcy/cd/index.htm