Generally, the best way to save money on tickets is to buy them in advance. Mousesavers has some links to cheaper tickets I think, but usually not much cheaper than just buying them yourself from Disneyland.com Don't wait to buy them at the gate! But do check out mousesavers Its a good site that has all sorts of information on DL and WDW.
As far as meals, you can go to the allears site and see menus and pricing for
Disneyland. Here is the link to that:
http://allears.net/dlr/dlresort.htm
If you decide to do a character meal or full service meal, make a reservation 60 days in advance by calling: 714-781-3463 Many restaurants fill up and don't take walk ups. Character meals are fun, but pricey. You'll see kids all over the parks getting character autographs. My daughter is 12 and still loves to do that. You can buy autograph books there or just take your own. Even a little notebook from Target works fine for that. They have ones at the parks that have a slot to fit a photo in of them with that character next to the autograph. I think those are around $10 each. Maybe ask your kids if they want to do that and if they do, allocate that money to buy them when you get there or take your own!
Most counter service places at DL and DCA have large portions so you can easily share meals. You can also take your own water bottles, juice boxes and snacks into the parks. For that matter you can take in sandwiches. THey say no food, but that isn't enforced. You cannot take glass bottles in however. But by taking your own water bottle, you can save a bundle. They are like $3 each in the parks. The counter service places give you free ice water, you just have to ask.
I would suggest buying a guide book like Birnbaums and looking at it with your family. I like that book because it has the height requirements for each ride. That way you can measure your kids, know in advance how tall they are and give them a heads up on what rides they can each ride. The color photos and descriptions of all the rides, shows and restaurants really is nice. Its an easy read and not expensive and most libraries stock it as well. I bought that for our first trip and it helped a lot!
Get to the parks EARLY, at opening. Make sure you check the calendar on the Disneyland website. They generally have that posted around 60 days out. Enter your dates and it will give you the park hours, times for parades and shows and the fireworks. See the fireworks, they are wonderful! We like to get there early, then go back to our hotel, rest, nap, take a swim then go back at night.
Don't try to see it all. That's why having your kids read the book with you helps. They can pick their highlights and once you have seen and done your highlights, the rest is just an added bonus! It sounds like you have a nice amount of time so you should be able to see most everything but there are always things that have to be saved for the next trip.
You will need to take the ART (Anaheim Regional Transit) from your hotel. You can buy a pass for that will save you money. Your hotel probably sells those. Don't drive and park in the parking garage. That costs time and money. Its much easier to take the ART. The Hilton may advertise they are just a couple of blocks away, but I think its a mile or two. Those "blocks" the nearby hotels say they are from DL are generally much longer than a typical block. So be prepared for that shuttle expense. Its not that expensive and I think kids under a certain age ride for free. The people at the Hilton can advise you of all that.
Hope that helps!