We took our kids last October to Disneyland (this year we're going to DisneyWorld) and the best advice I found was at www.mousesavers.com It's mostly geared towards DisneyWorld, but there is an entire section on Disneyland that is VERY helpful. It tells you the best (and worst) times to go, how to navigate the park, etc. Be careful of non-Disney hotels that say they are "a few blocks" from the parks because while technically they may be, it's not alwasy easy to walk to the park. If you really want to walk, then stay at a Disney property, otherwise rent a car if you fly.
I'm not sure how old your kids are, but our kids were 3 and 5 when we went and so we'd eat breakfast before hitting the park when it opened, eat lunch at the park and then leave around 7 pm and get dinner before heading back to the hotel. It's VERY expensive to eat inside the park (tips for saving money on park food is on MouseSavers.com) so that save a lot of $$$.
Also, the best place to meet Disney Characters is at the Back Lot at California Adventure. They were always out and about there. We went to both parks for a total of 5 days and it was the best experience ever!!! I hope you have as good as experience as we did.