I have to say, you are going to love it there. Disneyland is my home park, and Halloween time can be a lot of fun. Things you should keep in mind for your mornings are: Space Mountain Ghost Galaxy. The first thing I noticed last year when they brought this overlay out was the fast passes were gone before noon each day, and could have a stand by time of over 2.5 hours. Grab one when you first get in, and consider getting at least one more as soon as you can since you can use them any time during the day. The Haunted Mansion overlay is a lot of fun, but make sure you get over to the Indiana Jones and the Temple of the Forbidden Eye. WOW! One other bonus is this ride is also a single rider attraction.
I would recommend listening to, (or again if you already have), WDWRadio episode #58. This is Lou's experience in the park a few years ago with his friends.