I agree with Ben: oil, filter, and belts. Also the cambelt tensioner.

(I really should take my own advice one of these days

)
An engine swap can be done in 1/2 a day on the driveway with a mate, but only if you've done it before and nothing goes wrong I reckon.
Of course, things like exhaust manifold nuts and engine mount alignment can be a b!tch, so I would allow a good weekend.
An engine crane would be useful if you can borrow one, but if not, multiple jacks and straps should do so long as you have a helper or two.