Unfortunately, because construction was so common (ie routine and boring) and construction was taught via apprenticeships rather than learning from books, there isn't a whole lot of written evidence about your average medieval building site. However, we know a lot about how powered machinery worked mechanically, because some machinery survives into the present day. A variety of types of powered machinery and the ways in which they could be used are also depicted in manuscripts. It was fairly common for a manuscript to have illustrations relevant to the text, so there are many drawings of castles and cathedrals being built.

There were some obvious advantages to having powered machinery, especially cranes. In cathederals, for example, the only way to get large blocks of stone up to the roof or the towers was with powered machinery - it's not like a 400 pound block of stone can just be hauled up a ladder. It was also precarious to expect scaffolding to support large stone blocks, so it was easier to build the crane on the stone tower and trust that can take the forces involved. What would often happen in the construction of towers and other tall buildings, as depicted in manuscripts, was to build a crane on each floor of the tower and haul the blocks up, then the next floor would be built around the crane, then the crane would be disassembled once the exterior was in place. This would then enable the builders to start working on the interior. If the stone was a little lighter, such as if they were building or repairing a city wall rather than trying to build a 60m high cathederal tower, then small cranes could be put on scaffolding rather than in or on the building itself. In a city, that latter method would be much more common. The fact is, stone is heavy and cranes, winches, hoists etc. are the only way to transport it safely and efficiently.

These machines existed side by side with more manual methods of transport and construction. For short projects (ie repairing a few fallen roof tiles), building a crane was a waste of time, resources, and money. In those cases, people would simply carry things up a ladder onto the scaffolding. This is just conjecture though, because nobody went to the trouble of depicting or describing the local butcher having his roof redone. Depictions of construction will often have big cranes alongside labourers simply carrying stuff up ladders, or going up a ramp with a wheelbarrow.

As you can probably tell by this point, the extent to which cranes and other powered machinery was present on a medieval building site depended on the materials they were working with. Light materials that were easy to carry did not require cranes. Maybe, if the work was going to take a while and manually carrying stuff up ladders would become a pain, then small winches and hoists could be used. There are a few depictions of builders making contraptions that are basically just fishing rods but bigger, to which bags of stuff could be attached and winched up. But generally speaking, cranes were reserved for major construction projects that involved heavy materials. Cathedrals, castles, palaces, and city buildings would need this machinery, but a rural farmhouse would not. It wasn't so much about saving labour, but the limits of physical strength.

The other space in which powered machinery would be everywhere would be the docklands and harbours of major coastal cities, where cranes were used to load and unload cargo far faster and more safely than people ever could by gangplank. These dockland cranes tended to be much larger, and required more people to use. This is because construction work was partially limited by the speed at which masons could work, whereas to a merchant (and city authorities hoping to get harbour fees and tax the movement of goods, as well as charge to use the crane), time is money. The faster a crane could operate, the more cargo could be moved, the more ships could operate at the docklands in a given space of time, the more ships could be charged to use the crane is a space of time, and the more money could be made. Crew would also reconfigure their rigging and masts to create hoists and pulleys to move cargo. You can read more about the movement of cargo in ports (besides dockland cranes) in this answer by u/terminus-trantor.

Sources

Fitchen, John. The construction of Gothic cathedrals: a study of medieval vault erection. University of Chicago Press, 1981.

Matthies, Andrea L. "Medieval treadwheels: artists' views of building construction." Technology and culture 33.3 (1992): 510-547.