Theoi.com has a nice article about Olympos, citing as main source Homer's Iliad.
It was essentially an ancient akropolis--a fortified hill-top and
palace complex--located just below the peaks of Mount Olympos. The
golden gates of the heavenly fortress were guarded by the three Horai
(Horae) and it contained the palace of Zeus, lesser palaces for the
other gods, and stables for the immortal horses. The buildings were
built of stone with bronze foundations and were surrounded by
cloistered courtyards with golden pavements.
The main structure was the palace of Zeus. It had a fairly simple
layout--as was typical of ancient Greek palaces--with a central hall,
private bedchambers and storage rooms. The golden-floored hall served
as both a council chamber and feast-hall for the Olympian gods and
provided them an expansive view of the world below allowing them to
observe mankind from the heights. The golden tables and tripods of the
feast were automatons animated by the divine smith Hephaistos
(Hephaestus), and trundled in and out of the hall as required.
Before the palace of Zeus was a large, cloistered courtyard where the
full assembly of the gods would gather--including all of the earth-,
river- and sea-deities as well as nymphs. The peak of Olympos
functioned as the secondary seat or throne of Zeus, apart from the
rest of other gods.
The Olympian akropolis lay above the clouds and the paths of the
stars, near the apex of the solid bronze-dome of the sky. It existed
in the zone known as the aither--the bright upper-air of heaven or
shining blue of the sky. The gods feasted on ambrosia and nectar,
substances collected from the meadows of the earth-encircling river
Okeanos or the smoke of sacrificial offerings wafting to heaven.
Among the most descriptive passages of the Iliad quoted in the article, you can find these:
Afterwards when the light of the flaming sun went under they went away
each one to sleep in his home where for each one the far-renowned
strong-handed Hephaistos had built a house by means of his
craftsmanship and cunning. Zeus the Olympian and lord of the lightning
went to his own bed, where always he lay when sweet sleep came on him.
Going up the bed he slept and Hera of the gold throne (khrysothronos)
Homer, Iliad 1. 493 ff
The pressure held their heads on a line [the Greek soldiers], and they
whirled and fought like wolves, and Eris (Hate), the Lady of Sorrow,
was gladdened to watch them. She alone of all the immortals (theoi)
attended this action but the other immortals were not there, but sat
quietly remote and apart in their palaces (dômata), where for each one
of them a house had been built in splendour along the folds of
Homer, Iliad 11.72 ff
She went into her chamber, which her beloved son Hephaistos had built
for her, and closed the leaves in the door-posts snugly with a secret
door-bar, and no other of the gods could open it. There entering she
drew shut the leaves of the shining door, then first from her adorable
body washed away all stains with ambrosia, and next anointed herself
with ambrosial sweet olive oil, which stood there in its fragrance
beside her, and from which, stirred in the house of Zeus by the golden
pavement, a fragrance was shaken forever forth, on earth and in
Homer, Iliad 14.153 & 14.225 ff
The same quotes can be found in the English edition of the Iliad at the Perseus site, but in some cases they have different number citations: Hom. Il. 1.493, Hom. Il. 11.47, Hom. Il. 14.154.
The Odyssey doesn't seem to add much, except that the weather there was quite fine:
So saying, the goddess, flashing-eyed Athena, departed to Olympus,
where, they say, is the abode of the gods that stands fast forever.
Neither is it shaken by winds nor ever wet with rain, nor does snow
fall upon it, but the air is outspread clear and cloudless, and
over it hovers a radiant whiteness. Therein the blessed gods are glad
all their days, and thither went the flashing-eyed one, when she had
spoken all her word to the maiden.
Hom. Od. 6.1