If original plugs, they should last 100K.
If automatic trans, think about changing the fluid when you get some spare time. Drain and refill. This gets out 2/3rds of the fluid but if done on a schedule will result in having decent fluid in the trans. This goes a long way to extend transmission life! If you can get to it, also change out the differential fluid at this time, assuming it has a separate fluid housing. I would change the trans fluid every 30K. Fluid overheating such as in stop and go traffic kills transmission fluid, and in turn this kills transmissions.
You can use a turkey baster to remove the fluid from the PS reservoir and refill. Do this a few times over time and the fluid will be clear. If the fluid gets dirty again in 10-15K miles do the job again.
If you have ABS, flushing out the old fluid for new will go a long way toward preventing system problems. If not it still prevents corrosion. Have a friend help or pickup a bleeder kit. Use only fresh fluid from a new, sealed container. The experts state every few years, the fluid in the reservoir should be clear not dark.
As suggested drain and flush the coolant system when you get an opportunity. I would suggest every 30K.
Changing fluids goes a long way to prevent problems! It is very cheap insurance and all of these things are DIY jobs.
Click on the link below to find the service manuals for Camry.
http://oregonstate.edu/~tongt/camry