Since young Scout is the narrator, she describes parts of Maycomb as they become relative to her and others around her.

In chapter 1, Scout provides the background of her family and some history of the area. She also describes Maycomb as the county seat, an old town, where Atticus is related in some way to almost everyone. Her focus then turns to the Radley house which is dilapidated.

The Radley house jutted into a sharp curve beyond our house. Walking south, one faced its porch; the sidewalk turned and ran beside the lot. The house was low. It was once white with a deep front porch and green shutters, but had long ago darkened to the color of the slate-gray yard around it.  Rain-rotted shingles drooped over the eaves of the veranda . . . the remains of a picket [fence] drunkenly guarded the front yard—a "swept" yard that was never swept . . . (Ch 1)

Two live oaks are at the edge of the Radley lot, and their roots have buckled the "side-road" where the children walk as they come home. It is in one of these trees that Boo places gifts in a knothole.

In chapter 4, Scout describes her neighborhood, which is not far from town. The house in which Cecil Jacobs lives is at the far end of the street, next door to the post office. Miss Rachel lives next door to the Finches, and Mrs. Dubose lives two houses away from the Finches. Across the street from the Finches' house is Miss Stephanie Crawford's home. North of her house is Miss Maudie's house. Jem and Scout are allowed to play in Miss Maudie's yard as long as they do not jump on her grape arbor. "She loved everything that grew in God's earth, even the weeds." Only nut grass was not allowed in Miss Maudie's yard because it would take over a yard if it were not removed.

In chapter 12,  Scout describes in detail the First Purchase African M.E. Church in the Quarters outside the southern town limits:

It was an ancient paint-peeled frame building, the only church in Maycomb with a steeple and bell. . . . First Purchase was unceiled and unpainted within. Along its walls unlighted kerosene lamps hung on brass brackets; pine benches served as pews. . . . It was dim inside, with a damp coolness. (Ch.12)

In chapter 15, Scout describes the "miniature Gothic joke" that is the jail. Only one cell wide, it has a second cell stacked on top of the first. The small building has "tiny battlements and flying buttresses." The front is covered with red brick, and above the thick steel bars are "ecclesiastical windows." The jail is squeezed between Tyndal's Hardware and the newspaper office on the northwest corner of the square. On the other sides of this town square, there are various stores. There is also the Maycomb Bank building in which Atticus has his law office.

In chapter 16, the courthouse and its grounds are described, along with the lawn and public hitching rail outside. The courthouse is "fairly reminiscent of Arlington in one respect: . . . the concrete pillars supporting its south roof were too heavy for their light burden." (Ch.16) Inside the courthouse, there is the balcony where the black people sit. On the day of the trial, all the seats are taken in the main part of the courtroom, so the children innocently sit with the Reverend Sykes in the "Negro section," as it is called. The "colored" balcony runs along three walls, much like a second-story balcony; from this position, a person can see everything. Underneath long windows on the main floor is the jury seating. Mr. Gilmer, the circuit solicitor, and Atticus Finch and Tom Robinson sit at two tables. The witnesses sit on cowhide-bottomed chairs.

First of all, be sure to check out the excellent "Map of Maycomb" graphic provided by eNotes. It gives a good visual representation of the main street of Maycomb as well as the courthouse square with many citizens' names and businesses mentioned. I've included the link below.

As for quotes and descriptions, you can find many in the following chapters.

• Chapter 1 gives a good description of the Radley House.
• Chapter 4 places the locations of several of the Finches' neighbors.
• Chapters 5 and 8 give the best descriptions of Miss Maudie's house.
• Chapter 9 gives a glimpse of Finch's Landing.
• Chapter 11 concentrates on Mrs. Dubose's house.
• Chapter 12 describes First Purchase Church.
• Chapter 15 describes many buildings around the courthouse.
• Chapter 16 describes the courthouse in detail.