This is a key Madrid metro and local commuter train station, right below Puerta del Sol, a main plaza in a central area of the city. This extends 3 levels below ground--the metro lines 1, 2 and 3 (blue, red and yellow respectively) stop here as well as Cercanias (local commuter) trains C3 and C4 lines.
Overall the station is pretty clean, they have electronic signs showing next train destination and arrival times for each platform. There are also a handful of food and convenience vendors located in the station too.
Touch screen ticket machines are available to purchase tickets, they take cash or card depending on the machine, generally card is more common. I didn't see (or maybe missed) offices to purchase though during busy hours station workers often stand by areas in the station with multiple ticket machines to help assist. Machines provide directions in Spanish and if you need other languages then look for an on-screen button with various flags to select the language you need.
You need to scan your tickets at the turnstiles to enter the boarding platforms for both metro and Cercanias. The metro lines are located one the first sub level and Cercanias further below. Always build in enough time to descend into the station since it can take several minutes to reach your platform. read more