When installing anything on a wall, your best and safest option is to attach to the wall studs. The problem being in houses that aren't currently being built or extensively remodelling is that these are covered with sheetrock and paint.
Wall anchors exist, but these are limited in use due to their weight limitation, most are limited to a maximum of 100lbs, which isn't going to cut it for a kitchen cabinet with a full load of china.
Two methods exist to detect these important and necessary beasts.
Stud finders cost money, are slow to use and in my experience far from perfect at finding studs.
My preferred method utilises a cordless drill and a one 1/8th or similar drill bit. Working in the area that will be covered by what's being installed, pick a starting point and run the drill into the wall, if you are still getting resistance after three quarter of an inch depth, you've found the wood!
Good starting points are directly above or below electical outlets, or switches, as these are nailed to wall studs 99% of the time.
Once you've found your first stud, measure 16" from it where you should find the next, test again, then move on. Occasionally, on exterior walls, studs are spaced on 20, or 24 inch centres.
