30k miles is a good tranny fluid change interval, IMO. Be sure to use only the Honda fluid, as no one else makes a compatible fluid (anything you find at AutoZone, Wally World, etc isn't the proper fluid unless it is branded "Honda").

There is no filter in the traditional sense of a flat metal canister that is attached to the bottom of the tranny and resides in the pan area; but there is still a filter (yes, another Honda myth broken...). Consult the factory manual and there definitely is one. How often should you change it? Well, I think that most manufacturers try to extend their maint intervals too long in order to make the maint costs appear cheap when you are comparison shopping. I would change it every 60k (every other fluid change). It is a canister type filter and it resides on top of the tranny case, behind the battery and beneath the air filter box.

Never changing this filter is akin to believing that some coolants and lubricants are lifetime - lifetime just means that if you don't do the maint the fluid lasts as long as the part itself does, which of course has it's life shortened considerably if you don't do the maint. - a nested loop if you will. Nothing lasts forever, the question is only really is it cost effective? I always err on the side of too much maint rather than not enough. Honda believes in using only as much fluids as absolutely necessary - witness the 4.3 quarts of oil they deem adequate for the 3.2 litre engine. VW puts in 7 quarts for a smaller V-6 and 13 quarts for a 4.2 litre V-8. Possibly overkill. I change my oil with synthetic every 3k in this car, as I believe the oil sump doesn't hold enough oil. I say change the darn tranny filter. YMMV.