Why do large aircraft have their engines mostly on the wings, while smaller ones tend to have them in the tail or the tip?
Small aircraft need very low mounted wings to allow for a decent cabin height. The last commercial airliner which required the passengers to climb over the wing spar on their way to their seat was the Boeing P-247. Low wings do not allow the necessary space for engines, so the next best location is on the rear fuselage. Also, small aircraft have a relatively short fuselage, and the gear can be made short (and light) without risking a tail strike on rotation.

Fighters need to have small moments of inertia, especially in roll, so they cannot afford to put engines on the wings. Even the Me-262 was initially planned with fuselage-mounted engines, that's why it had this peculiar triangular fuselage cross section. Only when the engines grew in diameter during development they had to be placed on the wing.

Pros of rear-mounted / fuselage-mounted engines:


The wing is clean, having low drag and optimum conditions for lift creation.
The engines are easy to access (if mounted at the rear fuselage. Different story with buried engines!).
Smaller vertical tail needed for asymmetric thrust conditions.
Shorter, lighter landing gear possible (if rotation capability is not compromised).
Low roll inertia.


Cons of rear-mounted / fuselage-mounted engines:


No bending relief for the wing; heavier wing spar needed.
No help in flutter supression (a mass ahead of the elastic line helps).
Possible interference with wing wake at high angle of attack.
Forces the tail to be a T-tail configuration.
More structure needed to carry the thrust forces forward.
Intake noise is more audible, especially for passengers in the rear seats.


This picture of a Cessna Citation X should illustrate the point nicely.