The Elf character class only takes up one page in the book, although it does take up the full page. The picture of an Elf, together with a Halfling, is on the facing page describing the Halfling class.
What do we learn about elves as a D&D trope first of all? The description draws heavily on both the elves of Tolkien and those of Poul Anderson (and possibly others), rather than directly from mythological or folklore sources. Not having been exposed to either Tolkien or Anderson but having been exposed to plenty of myths, legends and fairy tales as a child, when I first read that "elf" was a class in the game, I thought of tiny fairy/pixie type creatures, or Keebler elves baking cookies in a tree/making toys for Santa at the North Pole. Boy, was I happy to find out I was wrong!
We're told that Elves like to spend time frolicking in nature, love magic and artistically crafted items, and tend to avoid humans. They're just a tad shorter than human normal, thin, and graceful.
As a D&D class, they are part Fighter (but not as tough) and part Magic-User. It's not obviously stated, but the price you pay for versatility like this is advancement at half the rate of a Fighter.
Elves get several special abilities. I discussed infravision last post, with the Dwarf entry. The text is just copy/pasted here.
The languages an elf begins play knowing are Common, Elf, Gnoll, Hobgoblin, and Orc. It can help to have an Elf and/or Dwarf in the party to be able to converse with many monsters. This also gives Elves a slight leg-up with Charm Person spells as they are more likely to be able to communicate with charmed minions. Elves need Strength and Intelligence for a Prime Requisite XP bonus, and to get the +10%, Int is favored, so they are just as likely as Magic-Users to have bonus languages from Int on top of the racial languages.
Elves have twice the chance to detect secret doors as other races, 2 in 6. Of course, this is only half of the stated chance from OD&D, where Elves had a 4 in 6 chance and everyone else had the 2 in 6. I don't know exactly why this change was put in. Was it too easy to find secret doors? Any more, I think it's better (more fun for the players, more fun for the DM) if the players DO find secret doors often. I'm still using the by the book numbers in my infrequent megadungeon games, but I may adjust this in my house rules document.
Elves are immune to ghoul paralysis. This is one of the things that got me back into old school D&D gaming (thanks again, to Superhero Necromancer). No explanation is given for this, although I now know that it comes from Chainmail, where the elf troops were not held paralyzed by undead troops if they came into contact.
Finally, as we all know, Elves can cast spells just like a Magic-User. We're advised to read those pages (having previously been advised to read the Fighter section to get tips on playing a warrior-type PC). What we're not told again is that advancement is slow. I remember introducing several friends to the game, and almost always they'd want to play an Elf to get the "best of both worlds" effect. Of course, since most of them never played more than once or twice with me during recess at school, it didn't matter that they had no chance to get to level 2.