Growth of opposition to Tsarist rule

Emergence of opposition groups including the:

Liberal party that first stood for fairness and reform
As the revolution progressed, it lost its influence and its reputation failed
Those who wanted the Tsar back were too afraid to admit it, and thus, joined the Cadets.
As a result, the Cadets became a reactionary rather than liberal party, full of people who wanted to destroy its original cause from the inside.

Formed to implement the terms of the October Manifesto (oct, 1905)
Participated in Duma elections, and in the Third Duma (1907 - 1912) they won by far the greatest number of seats.
Initially supported Stolypin's methods, but slowly became disillusioned with his recationary policies
In September, 1915, after the outbreak of the first World War, they were critical of how the government was run
Eventually joined with the Constitutional Democrats to advocate their plans for reform.

They thought violence was the necessary means by which Russia should be governed
Critical of the Tsarist regime and how the country was being run
Wanted land to be taken from the nobility and given to the peasants
Responsible for numerous assassinations of officials, including the Okhrana
Got widespread support from the peasantry in the countryside, but also some from the towns

December 1905: the party held their first meeting, in which they agreed upon 5 important points:

Russia needed an armed uprising
Russia should become a federal republic
Terror could be used to advance their caused if required and if given permission by the highest authority in the party
Private estates should become property of the state

They played little part in the 1905 revolution
They got 36 seats in the second duma (post 1906) but didn't take part in any other elections for the Duma.
When revolution broke out in March, 1917, the Army looked to them in the Nation's time of crisis. However, from there, their position only went down.
When the Provisional Government was still in place, they tried to form stronger ties with Lenin and the Bolsheviks. They failed
In 1919, their relationship with the Bolsheviks was so bitter that they even planned Lenin's overthrow. On paper, it seemed very unlikely, but in the face of the Civil War, it became a possibility.
They became unsuccessful because of their lack of support. Within the party itself, there were frequent disagreements as to how things would be run, which made them inefficient

The Mensheviks were the so-called minority (though this was rather untrue). They were more relaxed and wanted a government system loosely based around democracy. They were hesitant about using violence as a means of change, and, while they wanted to follow capitalism, they did not want an. One of their most notable members was Trotsky (at least, at first).

The Bolsheviks were the so-called majority (again, untrue) and wanted to use violence as a means of bringing about change. They wanted an organised and strictly run capitalist society, led by Lenin. He was inspired by much of Marx's writing and did not want any Tsarist police infiltrating his party. He wanted party members that could follow orders quickly and efficiently.

Summary!

The constitutional democrats (cadets) once stood for fairness and reform but fell into ill repute because their party was used as a desguise by reactionaries who wanted the Tsar back
The octobrists came into existence as a result of the October Manifesto and wanted reform as well. They were popular, and lasted a short while before joining with the Cadets.
The social revolutionaries were violent and wanted Russia to be a federal republic. They got influence at the start of the 1905 revolution, but soon fell, and the Bolsheviks refused to let them re-gain their old power.
The social democrats were also violent, for the most part, and wanted to take land from the rich to give to the peasantry. They killed a few government officials, too.

The Social Democrats split into the Mensheviks and Bolsheviks because of their opposing views. One wanted a loose democracy and the latter wanted a strictly run communist regime. Lenin led the Bolsheviks.