There are two kinds, and you choose when you start the ladder. A doubles ladder holds pairs. A pair takes one place on the table and has one rating between them, and both of them can record a match and confirm one. Nobody can be in two pairs on the same ladder. The pair stays together: to change who is in one, take the pair off and add the new one. The old pair keeps its record; the new one starts where a new pair starts.
A rotating doubles ladder holds people. Partners change from match to match, a match names four players, and the rating is yours. It is worked out from the two sides' averages, so a win with a weaker partner moves it further. Be clear about what that number is: the ladder cannot tell carrying a partner from being carried, and one result says as much about who you were paired with as about you. Over a season the partner draw washes out. Any of the four can put the score in, and either opponent confirms it.
Everybody the club puts in a box joins the club-wide ladder automatically, and that ladder can be singles or rotating doubles, because either way an entry is one person. A ladder of fixed pairs is never filled in that way, because nothing can guess who plays with whom, so you add the pairs yourself.