Doctor Who: The Newbies Guide
Attack of the Cybermen
This is the first story in Season 22. Like all stories in this season it has 45 minute episodes.
The sixth Doctor is brash, stubborn, and often condescending and arrogant. He wears a bright multi-coloured coat.
Perpugilliam "Peri" Brown is an American botany student from the 1980s who decided to join the Doctor on his travels during Planet of Fire. In The Caves of Androzani, the fifth Doctor sacrificed himself to save her life. She stayed with the newly regenerated Doctor in The Twin Dilemma despite post-regeneration trauma that led him to attempt to strangle her.
Recurring and Historical Characters
The Cybermen originally came from the planet Mondas, a twin planet to Earth. The planet somehow left its orbit, travelling into deep space. In order to survive its people started replacing their body parts with cybernetics. Eventually they became more machine than man, removing their emotions. Now much stronger than humans they seek only to survive and convert human beings into more Cybermen. The Doctor has encountered them numerous times. In Tomb of the Cybermen, the Doctor encountered a group of Cybermen who were asleep in "tombs" on the planet of Telos. In Revenge of the Cybermen, he discovered that gold dust clogs their breathing apparatus, and is fatal to them.
Lytton is a mercenary who encountered the Doctor whilst working for the Daleks in Resurrection of the Daleks.
Whilst Tomb of the Cybermen gives a bit of background to the Cyber-Tombs on Telos, it is unnecessary to understand the plot.
Lytton's previous appearance in Resurrection of the Daleks is also fairly irrelevant to the plot.
Having said that, there are a couple of continuity infodumps and gratuitous continuity references. If you're not familiar with the history of the show then these are best ignored.