The First Floor

"(Lockhart) set off back to the castle with Harry, who was wishing he knew a good Vanishing Spell, still clasped to his side. 'A word to the wise, Harry,' said Lockhart paternally as they entered the building through a side door [from the courtyard, so they're on the ground floor]...Deaf to Harry's stammers, Lockhart swept him down a corridor [the ground floor corridor that runs opposite the Great Hall, probably] lined with staring students and up a staircase [so now they're on the first floor]...They had reached Lockhart's classroom and he let Harry go at last."

has windows

had an iron chandelier until Neville was hung from it by his ears by pixies and it broke off the ceiling.

blackboard through which Binns enters and exits the room

Has a window through which Hedwig could enter; the window has thick glass and a narrow ledge.

Just up the corridor from Binns' classroom, in the direction of the marble staircase, is a window with a view of Hagrid's cabin

up the marble staircase and down a hallway, on the first floor.

Her office has a fireplace with a mantelpiece, and the entrance is evidently within easy walking distance of Myrtle's bathroom. The fireplace can be connected to the Floo Network when necessary.

At least one of her windows overlooks the Quidditch pitch.

Some of the corridors along the route from her office to the entrance to Gryffindor Tower have windows overlooking Hagrid's cabin.

To get from the DADA classroom to McGonagall's office, take a corridor from the DADA classroom to the nearest flight of stairs leading down; McGonagall's door is on the left.

lots and lots of beds with white sheets

Madam Pomfrey's office

privacy screens

bedpans (Ron once had to scrub them for detention)

moved to the third floor in 1995-1996