I don't do feeders myself (living in an apartment building with no balcony), but there are some good books on the subject.

Main issues with feeders are choosing a feeder design and feed that will attract the birds you want, making a commitment to keep them stocked over a period of years, keeping them out of reach of predators like cats, and keeping them clean, because feeders can be a source of disease due to problems with cleanliness, and because they bring certain birds into closer proximity with each other than they might be in nature.