Full sun. Deciduous with distinctive palmate leaves and sloughing bark. Sycamore is very big, very tall, and fast-growing. (It isn’t especially long lived on dry upland sites though.) It prefers growing close to water; try to pick downhill sites that will receive runoff during rain events.
Pruning is always optional. Cuts should only be made at a bud or branch; in general focus on minimizing dead, damaged, or rubbing branches. As with any tree remove no more than 25% of the total canopy during any five-year cycle. To maintain a healthy specimen, leave the upper 2/3 of the trees height uncut and never remove more than the lowest third of the tree in a single pruning period — for example on a 12-foot tree stick to the lowest 4 feet.
Mulch with about 2″ of wood chips or pine bark wherever possible. (In general a tree’s mulched area should be six feet at minimum.)