The park has vastly improved since '96. California Adventure is where the parking lot used to reside, and now they have Downtown Disney inbetween the two parks. Their website at
www.disneyland.com has the maps, with a brief description for each and every restaurant and ride.
And, of course, you have all the experiences and suggestions by those at Disney Central.
You might be saddened, too, as they removed the rocket rides, and Swiss Family Treehouse, and the Country Bears.
But depending on how long you stay and how much you want to do while you are there, to try and accomplish all comes close to five days. Others might disagree, but my girlfriend at the time went up for two days at a time, which made it worthwhile, but we lived in San Diego at the time. I would suggest five days to a week if you can afford it.