One way to easily identify symbols is to look at each person and object and ask yourself what it represents. Since Lord of the Flies is allegorical, almost everything and everyone is a symbol. I will describe some for you here.
The conch shell is introduced early on. It is used by Ralph to call the boys together, and it immediately adorns him with leadership qualities in the eyes of the boys.
The being that had blown that, had sat waiting for them on the platform with the delicate thing balanced on his knees, was set apart. (ch 2)
You can hear the conch “for miles” and Piggy comments that it is valuable—which it is, as a symbol of power. The boys pass around the conch, and the one who has it talks.
Jack pointed suddenly.
“His specs–use them as burning glasses!” (ch 2)
Piggy’s glasses symbolize his intelligence and his civilization. When humans conquered fire, it was a huge step forward for our society. The same is true for the boys when they use the specs to create fire. However, the ability to harness fire does not necessarily mean that one can completely control its destructive potential. The boys destroy the island because they open the Pandora’ box of fire but cannot control it.
Ralph is overcome with giddiness once he realizes they are on an island, a romantic notion for sure.
He patted the palm trunk softly, and, forced at last to believe in the reality of the island laughed delightedly again and stood on his head. (ch 2)
The island itself symbolizes the boys’ isolation and regression. With no vestiges of civilization and no adults, the boys are completely on their own.
Although most of them do not realize it, the beast represents their inner-savagery. The boys are afraid of the beast, but can never quite pin it down. The “beastie” is described as a “snake-thing” (ch 2). Some of the younger kids insist that the “beastie came in the dark.” Jack’s reaction to the idea of the beast is to hunt and kill it.
“Ralph’s right of course. There isn’t a snake-thing. But if there was a snake we’d hunt it and kill it. We’re going to hunt pigs to get meat for everybody. And we’ll look for the snake too–” (ch 2)
However, the beast does turn out to be real—it is the boys, when they kill Simon and Piggy.
Characters are also symbolic. Ralph and Jack have contrasting leadership styles for a reason. Ralph represents civilization, and Jack savagery. Simon, the Christ-like figure, represents religion or culture. Piggy, as already mentioned, represents intelligence and man-kind’s ingenuity.