Check out the link below; it is actually in response to 15K mile maintenance, but it pretty much all applies to 30K as well. If you have a manual, I would recommend changing to synthetic (bring some Redline Mt-85 - 3qts - with you to the dealer to have them replace the transmission fluid). If you have an automatic, it is maintenance-free (per the manual). The in-cabin air-filter is about the only thing different from the 15K mile list - the dealer will probably charge $30+ for the filter and 1/2 hr labor for the damn thing. It's six screws to take of the glove compartment to install one, a great DIY.
15,000 Miles/12 months Scheduled Maintenance, what did you do?
Unless you have any issues with the check list in the linked post or you have a MT, just have the dealer do an oil change and be done with it if you don't want to spend the money. You can always ask them to check something specific for you. A good dealer shouldn't charge anything extra if you ask them to check easily accessible items while they're doing other work (i.e. an oil change) for you already.