Bob's right, it'd help me to know the year and model of your car. If it's
fairly new, here's what your owner's manual probably says you need to do:
-- Oil change
-- Tire rotation
-- Air filter
-- Inspect transmission fluid and change if necessary.
-- Replace coolant (for years 2005 and older).
-- Various inspections
If you're transmission fluid isn't yucky (and your car is newer than
I'd say draining and filling (not flushing) every 30k should be fine.
Technically, the manual indicates 105k is the interval for normal
but I'd feel much better with a 30k interval if it were my car. Heck, on
my 1992 Taurus, I'm changing the fluid and filter every 15k just to see
it'll improve this horrible transmission's life span.
Coolant should really only need to be changed based on time. For 2005
older, it's required every 2 years. For 2006 and newer, the first change
is at 5 years, and then every two years after that.