Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
This is mainly a build and setup guide for beginners that just want to start ranked games, this is a base that everyone should be aware of, and a knowledge you must have before starting to play ranked games.
Why such an setup?
Because this is the most viable one to play, obviously a setup should contain;
Any of the following ones work; Caitlyn, Tristana, Vayne, Graves, Corki, Urgot, alternativelly Ashe, but that is one of the most weakest AD carrys IMO.
Any of the following ones work; Alistar, Sona, Soraka, Taric and alternativelly Nidalee.
ANy of the following ones work; Karthus, Kassadin, Sion, Anivia, Annie, Brand, Cassiopeia, Kennen, Leblanc, Vladimir, Malzahar, Morgana, Orianna, Ryze, Swain, Veigar, and alternativelly Xerath(?).
Basically any champion can be a good jungler, the list would be enormous.
Some people choose to go duo AP, meaning two AP carrys, one mid and one top, this is something most people skip and use top to lane a offtank/bruiser, which can be any from Akali to Yorick.