The oil filter is changed with each oil change (every 3K miles). The fuel filter should be done with a tune up (refer to owner's manual) or go to our home page under DIY section. The air filter is changed when it is dirty. Based on road conditions and use, it can last different amounts of time.
If you have an owner's manual, it should list everything for you. If you don't have one, on our homepage, you should be able to find a general maintenance schedule.