hi friend...

its a simple question you asked.
but the answer depend on how you drive the car?

if you abuse your car, then it needs more maintenance...

the basic things is...
1)engine oil and filter replacement.
(for normal cars if you are using ordinary oil, then change it every 5000km. if you are sing synthetic oil, then change it after 10000km. in BMW they use ordinary oil and need to change at 10000km)

2)transmission oil/gear oil replacement.
(for manual gear box its 20000km. and for automatic its 40000 or 50000 depends on brand.)

these are the main things.
apart from this, you must maintain the coolant level, brake fluid, power steering fluid, battery level. replace air filter at every 5000km (if it is paper filter) replace the fuel filter every 10000km, replace or clean the AC filters. replace the spark plug,(depend on the spark plug used)

break pads must be checked. its usage depend on how you drive. if it is less than 45% then its time to change. that is safe. (we can use till it is 10%)

check the bush and bearing, the soft you drive the longer it will last.

now regarding timing chain/belt.
in older days chains were used, and now a days belts are being used. the time for its replacement will be mentioned by the brand. because its different for different cars. the important thing is, you must change it before it breaks. if it breaks, it may damage your pistons, valves and head.

these are the things you can do by your self. now there are few more things. cleaning the fuel injector/carburetor, clean the piston and cylinder.
check the oil seal and oil pressure. checking the compression pressure, check the gap of spark plug. check the fuel pressure. etc etc....

have a safe driving.
do periodic maintenance..
good for you and your car....
also for the people on the road.........

take care