Congrats on your first trip! That's such a wonderful age to be taking your kids
For tips: this might sound a little odd, but I'd recommend going to
Youtube and watching videos of people walking around the parks and going to attractions. Maps are helpful, and we always revise before we go, but once you're in the parks, it's far easier to lose your bearings!!
Like Aust above me said, never underestimate time needed for Disneyland! People really feel you only need a day or two, as it's much smaller than Walt Disney World, but that's not the case! We spent 8 days end of 2010 and didn't manage to fit everything in! I'd say definitely 4 or 5 for a first trip would be a good amount of time! If you can only spare 1-3 days, make sure to plan which rides are 'must-dos' before you go!
Make sure to check which rides will be suited for your kids. If any of them are thrill seekers, make sure you use Fastpasses. Fastpasses are available at certain popular rides. All you do is insert your park ticket into a machine, and it'll allocate you a time frame for you to return to the attraction to ride with almost no wait!
For example, if you were to visit Space Mountain at 10am and the wait was 60 minutes, you could grab a Fastpass, which might say to return between 3pm - 4pm, where your wait may only be 5 minutes!
The official Disneyland site helps explain as well, if you visit the 'Guest Services' page.
Fastpasses are also great if you have limited time to visit the parks. You can ride the attractions with smaller lines, while waiting for your fastpass return time!
A tip I'd recommend would be to get a 1st Time Visit badge! You can get them from City Hall, which is to the left as you head under the Disneyland Station entrance. You don't really get anything from them, but CM's will notice and be able to offer additional help, and may sometimes give you tips or let you in on secrets if they know it's your first visit!
Check out 'allears.net' and click on 'Disneyland' at the top. Then go into 'Dining' on the left side navigation bar and then 'Disneyland Menus' from there. Take a look at the menus before you go, and make note of any foods you want to try and what fits with your budget. Most of the menus include the prices of the food, and it's updated regularly.
Make sure to sort out which nights you want to see the Night Shows (if you want to see them!) World of Color began in 2010, and offers a fast pass system for the show. It's an absolute must do for our family!
Make sure to get to Disney California Adventure park at 9am on the morning of the day you want to see it. Head straight to Grizzly River Run ride, where you can use the Fastpass machines to get your viewing tickets. It's a first come first serve basis, so to get the best view of the show, get the fastpasses early!
Disney gives some info on it too, under the Disney California Adventure page. If you click on 'World of Color' and visit it's 'Experience' page, it'll give details for fastpasses and recommendations.
Aladdin - A Musical Spectacular is a must see too! It's a 40 or so minute musical show, which in our opinion, is the quality you pay for when seeing a broadway show! It doesn't require fastpasses, but you do have to get in line. There are several shows throughout the day.
For your little one, I'd recommend to make note of all the bathroom locations on the maps. Also take a look at which parades you think she may be interested and plan them into your day.
For food for the kids, if they're picky eaters, consider getting groceries outside the resort and taking snacks into the parks. If you're able to get to a grocery store, I'd stock up on bulk-buy water bottles, because the park has them way overpriced!!
Have an AMAZING and magical time!!!!
Feel free to PM me if you have any questions or want any further advice

We've been visiting since I was around the age of your kids, and have family friends over there, so I consider SoCal a home to me
