I do not know when the full load of hotel rooms (or admissions) for Comic-Con International will be made available. I know the con folks are working like crazy to perfect the system before they open the floodgates. But just when you'll be able to book your rooms and badges, I can't tell you, nor should you count on me being your source for this information. If I were you, I'd keep a careful watch on the convention website.
Right now over there, there's an opportunity to reserve a room early at a reduced price if you'd like to stay out in the Mission Valley area. This is not that far from the action and a lot of folks prefer to be able to "get away" from the convention and just take the shuttle in each day. If this appeals to you, go read this page.
Every day or so, I get an e-mail from someone who's thinking of attending the con for the first time but is wary of the crowds and the hassles and the lines and such. Do not be wary. First off, you're hearing the occasional horror stories of the complainers. They're usually exaggerating the inconvenience and giving you the downside without the up. I know folks who follow each Comic-Con with vows of "Never again." Then three months later, they're asking me when badges will be available for the next one because they don't want to miss a minute.
Secondly, the reason it's crowded is that people have a great time there. It's one of those things you need to experience at least once…and if you do, you may discover you never want to miss it again. As George S. Kaufman once said, "You should try everything in life once except incest and folk-dancing."
If the size 'n' scope of Comic-Con intimidates you, there's an alternative. WonderCon, which is being held in Anaheim on St. Patrick's Day weekend — about a month from now — is kind of a junior version of San Diego. No one's sure how big it'll be this year because they've never held it in Anaheim before…but it can't be anywhere close to as big as San Diego. In its usual San Francisco locale, WonderCon has always been a friendlier, less mobbed gathering and it's operated by the same folks with the same skill and love of the media. You can get details about it here and you can book your badge and lodging right this minute.