Stages of the sharingan:
1. One Tomeo sharingan- This is the first level of the sharingan which gives the user the ability predict movements
2. Two Tomeo sharingan- this is the second level of the sharingan which merely enhances the users ability to predict movements
3. Three Tomeo sharigan- this is the third level o the sharingan which merely enhances the users ability to predict movements. It also allows the user to copy Jutsus within his ability to copy
4. Mangekyo sharingan- this is the fourth stage of the sharingan which enhances the users ability to predict movements and copy Jutsus. It also gives the user the possibility to unlock abilities like Tsukuyomi, Amaterasu, Susanoo, Kotoamatsukami, and kamui. (Sorry for any and all misspellings). Over use of this stage causes permanent blindness which can't be fixed with medical ninjutsu.
5. Eternal mangekyo sharingan- the final stage of the sharingan that decreases the Charka drain of the mangekyo techniques and prevents blindness. This also brings the ability to predict movements and copy Jutsus to its max potential
Users and the techniques of the mangekyo:
1. Susanoo- best user Madara uchiha. Sasuke and Itachi also used this technique
2. Amaterasu- best user Sasuke. Itachi and Madara used this Jutsu as well.
3. Tsukuyomi- best user Itachi. Sasuke and Madara if I am not mistaken can use this technique.
4. Kamui- obito
5. Izanigi- Obito
6. Izanimi- Itachi. Not sure who else
7. Kotoamatsukami- shisui
Known mangekyo sharigan user
1. Madara uchiha- EMS
2. Sasuke uchiha- EMS
3. Izuna uchiha- MS
4. Itachi uchiha- MS
5. Shusi uchiha- MS
6. Obito and Kakashi- MS
Over view of the uchiha clan:
The uchiha clan came from the older son of the sage of six pathes. The rivalry between the uchiha and senju a started than. When the sage chose the younger son to be his successor the older brother got upset and attacked his younger brother because he believed his younger brother wasn't worthy to carry on his fathers legacy. The uchiha's became the second strongest clan seconding only to the senju. After an intense battle where it became the obvious that the uchiha's where weaker than the senjus. Madara accepted Hashirama's offer and the hidden leaf was born. Tobirama later made the uchiha the head of the police force in Hidden leaf. Years later there was an attack on the village involving kyuubi and the uchiha got blamed. In order to prevent a civil war Itachi killed his own clan for the sake of the village.