Routine maintenance?
 

I only started bicycling regularly over the summer and I'm wondering what, if anything, I need to be doing on a regular basis to keep my bike in good working order. Oil anything? Change any parts? Anything at all? I've been riding around 500 miles per month, so my bike gets quite a lot of use.

Clean and oil the chain. I'd do it once a week or more. I prefer ProLink lube, but others may like Rock Star or something else. They all mostly work pretty well. Check the cranks and bottom bracket for tightness. Same with the headset. Check the wheels for true. A drop of oil on the pivot points of the derailleurs once a month is good too.

Make sure the tires are inflated properly every other day at least.

If you're riding in the rain, a bit more regular maintenance would be needed.