As far as 'small' and 'little' go, 'small' is used when just describing size. 'Little' is used with another adjective when there is some emotion involved.
"He was such a cute little pup." ('Cute' gives the emotion)
"His dog was somewhat small." (No emotion, just size)
As far as physical size goes, 'big' and 'large' are interchangeable when describing physical size. If we are talking about pure measurement or amount, then 'large' is used.
"He was a big/large man - at least 100 kilos."
"We spent a large amount of money on this project."
"He has a big estate."
"His estate covers a large area." ('Area' is a measured value)