If they use the same schedule as last year, the Believe in Holiday Magic fireworks show (which is VERY nice!) will be showing every night from about November 16 through the weekend after January 1. When the actual schedules will go up on the DL website is anyone's guess - might be mid-September, might not be until October. Most likely Fantasmic! will still be on off-season schedule, and only showing on Saturday and Sunday nights. The Christmas Parade should also be running daily by then.
Disneyland's version of the Candlelight Processional is only done on one weekend in December - it's usually the first weekend of December, which unfortunately for you would mean bigger crowds when you're there. But there's a rumor that it will be moved to December 8-9 this year.
Things not to miss: Haunted Mansion Holiday, Holiday "it's a small world", the Believe fireworks and the Christmas parade. Toontown is really nicely decorated. Oh, and be sure to spend a little time one evening near small world - after dark, about 5 minutes after the hour (and every 15 minutes after that) there's a choreographed light and music show. There's Santa's Reindeer Roundup over in the Big Thunder Ranch area - the kids can meet Santa, and there's also (free) crafts for them. Over at DCA there's Santa's Beach Blast in Sunshine Plaza where "Beach Santa" hangs out to meet guests. And the area back in Flik's Fun Faire has some cute decorations. And all the characters in both parks are dressed in their holiday best.
The tree in the lobby of the Grand Californian is very impressive, too.