Towered airports are a little more complex than non-towered airports, so it’s important to know what you are looking for on a sectional.  Entering the tower’s airspace without all the proper information and communications is a big deal and may get you in trouble.  This lesson will teach you what you need to know to stay safe and legal.
First, we can tell whether the airport has a control tower or not, just by looking at the symbol. A blue symbol indicates that an airport is towered, while a magenta symbol indicates a non-towered airport. For this lesson we are only interested in the towered, blue airports.
When figuring out if the airport is suitable for us to use, the first thing to look at is runway length. An airport with a solid circle and runway depictions inside indicates the longest runway is 1500-8069 feet long. An airport diagram that looks like a runway without a circle around it means that the longest runway is longer than 8069 feet.
Tick marks around the diagram show fuel services and other services are available from at least 10:00am to 4:00pm Monday-Friday. A star at the top of the diagram indicates a rotating beacon.  For airports with longer runways, the rotating beacon start will be located about where the rotating beacon is on the airport grounds, and there will be no tick marks.  It’s pretty safe to assume that a larger airport will have some kind of services, but always consult the airport/facility diagram first.
All other airport information is listed next to the diagram. This includes the airport name, identifier, control tower frequency and CTAF frequency, ATIS/weather frequency, elevation, longest runway length, UNICOM frequency, and other notes. While you can get almost everything you need just from the diagram, it is also important to check the airport/facility directory before you go. This will give you any other local information you need to know.