Since it is your first post - Welcome to the Forum. Also, to be clear, hydrometer readings that remain stable over 3 consecutive days usually mean that the primary fermentation is complete... but there are exceptions (some yeast have an infamous "stall").
Keep your fermentation (beer temperature, as Denny says) cooler than 64 or so, unless using a yeast that likes it warm (see Kviek and some Belgians) and watch it for an undisputed lack of further activity (airlocks are notoriously unreliable), then begin to take your daily readings (a week or so after pitching, if you want a typical period to use). Cheers!