Reading a Plat
You find Plat Book 'XX' and Page 'YY' in legal descriptions. You find the name of the plat in the description too. It's not always the name of the subdivision as it's known today. The street names can be different, too.
The book and page numbers don't change, though. So look them up that way. You find the in the County Courthouse wherever you are. In Palm Beach County, there are some private companies that sell them and also a great many plats are available on line at the Palm Beach County Building and Zoning site. (Search for plat maps online and specify whatever county you're in.) You need every page of the plat, too. The first page may contain easement and setback information you need. The other pages may contain curve and other information you need to know. You can't the chance.
Once you have the plat, you look up the block and the lot. The block is the land surrounded by, for instance, four roads. It can a water boundary, or be bounded by a park, or even just be on the edge of the plat. But it has measurements all the way around it in the form of lines of specific distance and direction. These lines are tied to centerlines in the street, or control lines on canals, or other lines in the plat. The lot is one of many in the block and is bounded, again, by lines of specific distance and direction. Every block is numbered or lettered. So is every lot, and they're all consecutive.
Plats show easements, and that's important. Easements control construction.
Plats also show how the land in the subdivision is tied to the section of land the subdivision is in. "Section" has a specific legal meaning (along with 'township' and 'range') that are related to the way the State's lands were divided when it became part of the USA. Before that the Spanish used land grants, which are something else. In addition to that. there are metes and bounds descriptions, and also aliquot descriptions.
Of course I have to add that the best way to read a plat is to hire a surveyor and ask him all the questions you want. That's what I do.