To some extent, Homer tells us what we need to know by, well, just saying it. He beats us over the head with epithets like "clear-headed Telemachos," "wise Penelope," or "Odysseus, master mariner and soldier." And you know what? We're cool with that. It sure makes keeping the character straight a lot easier.
Many characters' names in the Odyssey convey important information about their personality or role. We can't go into all of them, but let's look at three especially cool ones, starting from simplest to wackiest:
(1) "Kalypso," which is related to the Greek word "kalypto" meaning "to hide." This makes sense because, well, Kalypso hides Odysseus on her island for seven years.
(2) "Odysseus," which the poem ties to the Greek word odussomai, which means "to suffer." This connection is made when the young Odysseus receives his name from his grandfather Autolykos: "since I have come to this place distasteful to many, women and men alike on the prospering earth, so let him be given the name Odysseus, that is distasteful" (XIX.407-409).
The irony is that, even though Autolykos makes it sound like the name refers to inflicting suffering on others—since that's why Autolykos is "distasteful to many,"—Odysseus spends a lot of time suffering himself. (Although he sure does inflict a lot of suffering on others, too.) The Greeks often portray people as carrying out the will of fate without knowing it, like that poor sucker Oedipus. Do you think Autolykos might have been guided by fate in giving Odysseus this name? Or did he create fate by giving Odysseus that name?
(3) "Nobody," the name Odysseus gives to the Cyclops Polyphemos. Most of this is going to be Greek to you, but just bear with us and we think you'll see how awesome it is. The Greek word for "Nobody" is outis (pronounced OO-tiss). Now, it just so happens that this word can be changed into another one (don't worry about why) pronounced metis (MAY-tiss). So what? Well, it also just so happens that this word metis sounds just like a totally different word metis (MAY-tiss), which means "cleverness." This second word metis, meaning "cleverness" is very often applied to Odysseus; sometimes he's even called polymetis, which means something like "clever in many ways."
Coincidence? Not likely. When Odysseus is saying that he's "Nobody"—outis connected to the first metis—he's using his "cleverness"—the second metis. Then, when he makes the boneheaded move of telling Polyphemos who he is, the stupidity is underlined by the fact that he's no longer outis/metis and thus no longer acting with his full cleverness.
And then we can take it even further. How often is Odysseus's cleverness connected with him being nobody, or at least somebody other than himself? A lot. The guy is constantly using his wits to put on various disguises, even pretending to be the lowliest beggar—a "nobody" in a different sense—to achieve his goals. Pretty tricky, Homer.
In The Odyssey, you are what you do: the suitors show their dishonor by gorging themselves on Odysseus's food and wine without restraint; Odysseus perseveres in his repeated attempts to return home; Telemachos shows his piety by obeying Athene and going on a journey for news of his father; Penelope establishes her faithfulness and virtue by remaining loyal to her husband in his absence.
For women in the Odyssey, you're also what—and who, where, why, and when—you do. Just compare Penelope and Klytaimestra: the first is virtuous because she remains faithful; the second is treacherous because she doesn't. And that's pretty much all we need to know about them. Once we know that Penelope is faithful to her husband, we also know that she's wise, loving, and talented. Once we know that Klytaimestra isn't, we're not surprised that she ends up murdering her heroic husband.