The Cybermen was/were/are one of my all time favorite baddies on Doctor Who. There are those from our universe and those who are from another alternate universe and then based on the different time lines, different forms of Cybermen.
However, they first made their appearance on the episode called "The Tenth Planet". This episode was ground breaking for the show because it did three things.
1. Introduced the Cybermen to the show
2. This was William's last episode as the Doctor so they created "regenerations" to continue the show after this episode.
3. The Doctor saves the day at the cost of himself, regenerates for the first time and the 2nd Doctor appears.
The Cybermen come to earth to convert all of us into them in December of 1986. They came from earth's sister planet or also known as its twin planet named Mondas. Mondas is the 10th planet in our solar system. They bring their cybernetic people to earth on the Antarctica snow.
The Tomb of the Cybermen was created in 1997.
Revenge of the Cybermen happened on 1975-05-10.
Attack of the Cybermen happened on 1985-01-12.
Cybermen returned in episode 12 of season 7, 'Nightmare in Silver'.
Yes and no. Cybermen travel all over the universe, converting any and all lifeforms they can (and "deleting" any that they can't). So while some Cybermen USED to be human, not all Cybermen were (unless you count the ones from the alternate world in Season 2, since they began on Earth and had not yet had time to expand to other planets). They're similar to the Borg from Star Trek, if that helps.
Daleks: 20 Cybermen: 13 The Daleks
Yes, Cybermen do speak. They all speak robotic-ly and of the same tone.
Some of the Cybermen were humans who had a special implant that cut their emotions. The human brains were removed painfully and then put in steel suits. However some Cybermen were alien robots.
Cybermen - 2009 V is rated/received certificates of: UK:PG
probaly k9 with all his lazors but then again cybermen have lazors
The Daleks Vs the Cybermen is in the episodes 'Army of Ghosts' and 'Doomsday'
Cybermen are "upgraded" versions of mankind that do not have emotions. While "upgrading" you, they cut and slice and dice you into piece while you fill it all. Both the process of becoming one and seeing a Cybermen is scary!