How do you know that Odysseus was man known for guile in The Odyssey?
One of Odysseus' most famous features is his cleverness (or guile, as you say), and he exhibits this skill at many times during both Homer's Iliad and Odyssey. The most obvious (and probably most famous example) of Odysseus' intellectual prowess is his invention of the Trojan Horse, the downfall of the Trojan Empire.
In the Odyssey, there are many famous examples of Odysseus' smarts, but my personal favorite involves his encounter with Polyphemus, the hideous Cyclops. To save his men from being eaten alive, Odysseus' convinces the Cyclops that his name is Nobody, and then, once the monster has fallen asleep, he stabs Polyphemus' eye and escapes with his crew mates. Then, when his friends ask him who blinded him, Polyphemus answers "Nobody," and his friends laugh at him, and Odysseus and his men escape. This remarkable ingenuity is just one example of Odysseus' ability to cleverly deceive his enemies.
For starters, he was the hero who conceived of the Trojan Horse, the wooden construction built from ships that the Greeks used to steal into the walls of Troy and finally defeat the Trojans. It was a sneaky stroke of genius!
In addition, when he arrives home to Ithaca, he conceals his identity from everyone at first (except an old female servant who recognizes him regardless because she nursed him as a child), so that he can plan his revenge on the suitors without drawing their suspicion. Further, it will be all the more thrilling when he can best them in feats of skill and strength if they still believe him to be a poor beggar and stranger. In this, he is again both clever and deceptive so that his victory over them will be that much more complete and satisfying.