As an annual passholder for several years running, here are my suggestions.

ace-case makes a great point. For the larger attractions keep your eyes peeled for the "FastPass" machines. Basically, it holds your place in line and lets you return at a later time to sort of cut into line. The ticket will tell you what time to return to the attraction (within a two hour window) and at that point you come back and get in the special "FastPass" line which is much shorter than the regular line.

Most people enter the park through the Castle and into Fantasyland. You'll get around much quicker if you make your way up Main Street and head to your left, before you get to the Castle. That will take you to Tomorrowland. You'll be going against the flow of the traffic but the lines will be a bit shorter.

California Adventure is not as bad as everyone says. But, having said that, you can cover it in about half a day. It's big on atmosphere and short on rides, so if you're more of a "do stuff" than a "see stuff" person then yeah, breeze through it the morning of your second day and then head back over to Disney to revisit the stuff you like or the stuff you missed.

Weekdays are the best time to go, because the lines are not so long, but if you do a weekend, Sundays are better than Saturdays. But it is winter now, so even Saturdays won't be too bad.

Let me know if you guys have any questions. I'm at the park all the time. I'm a big Disney geek.