Hellobee Boards

I was at the OC Great Park for an event last year, and I have to say, it's underwhelming. The balloon and a carousel are really the only things there other than a giant tarmac. If you have to travel to get there, I'm not sure if it's worth it.

But I'm also from the East coast and used to landscapes having a lot more color in them...

The Irvine Great park is really nothing special. Going in the balloon was cool when it was free but now that they charge I wouldn't bother.

Irvine Regional Park is my favorite place to go with my family. Its a beautiful park with a lake and tons of trees. There is the train, pony rides, you can rent bikes and just lots of places to picnic and roam. They have a cheap little zoo there too.

If you want to do any shopping Irvine Spectrum is all out door and they have a carousel and ferris wheel and some fountains on the ground that you always see kids running through.

The most beautiful beaches I think are in Laguna Beach but for a good kid beach you can go to Dana Point Harbor they have a kiddy beach with no waves, there is a cool old Ship "the Pilgram" there and also the Ocean Institute where kids can learn about marine biology and different things like that.
They also have those Bikes you can rent there with the steering wheels where the parents pedal and the kids sit in the front. Lots of different grass areas where you can BBQ also.

In the Summer in Laguna Beach they have the Sawdust festival, I've never done it with kids but its a great adult thing and maybe your kids would be fine with it. It is all local laguna beach artists with their art work and its just a really pretty atmosphere with trees everywhere with lights and live music at night and they have a guy that does glass blowing that is fun to watch. Also during the summer in Laguna they have a free Trolly. You pay to park your car in a lot but then all day you can get on and off the Trolleys that go around the down town.

Downtown Disney is a fun place to go eat since you will be near Disneyland. They have rain forest cafe there that kids always love.

Pretend City is awesome.

In San Juan Capistrano there is a little petting zoo called Zoomars and a cute downtown area. The train stops there so maybe you could take a little train ride there?

Knotts Berry Farm is where I mostly went as a kid. Its cheaper than disneyland so if you are able afford another theme park (I know disneyland is a fortune) that is def a place worth going.

Oooh your kids are close in ages to mine (mine are 4 and 2), and I am an Orange County resident so I'll tell you what we typically do! It is going to be HOT in august, so we spend a lot of time at the pool or beach, but we also like to take it indoors instead of sweating it out in scorching sun.

There is an awesome indoor playspace in Lake Forest called We Play Loud - http://www.yelp.com/biz/we-play-loud-inc-lake-forest - it's $26 for our family of four. It's really fun, the staff are awesome, it's a huge space, and they're constantly sanitizing. There's a bounce house, fun indoor rides, ball pits, slides, etc. there.

For beaches, the most easily accessible one is probably Corona Del Mar and will be perfect for you and the kiddos. Laguna Beach is great too, but it gets super crowded and trafficky around that area and is going to be a further drive from Cerritos. Wherever you go, I recommend bringing a beach umbrella or pop-up tent because the sun is so strong. Eta: Actually, from Cerritos - I'd say Huntington Beach and/or Redondo Beach would be closer and they're both great beaches. Redondo Beach pier is nice and has a lot of good food!

OC great park is okay. It's a big empty space so its nice for people to bring their kids and their bikes and just have the kids roam around without fear of cars. We go here a lot. The main attraction there is the carousel. For $3 you get all day unlimited rides! It's a nice way to kill time. And there is a ton of grass and tables with umbrellas... so a great place to have a picnic too. It does have a small playground, but it's more for the younger toddler set, so I think your 3 and 5 yr old will get bored of that.

When it's hot we actually love going to South Coast Plaza too. It's a mall, but it also has a carousel ($2/ride), and there is the Lego store and Disney store right next to it that my kids love hanging out in. At the Lego store, there are areas where the kids can just play and build legos. At the Disney store, they're always playing shows/movies in the back, and there's a little table with coloring sheets and crayons where the kids can just chill and color. You can also get some shopping in too while you're there because Gap Kids is right next to the carousel haha.

Irvine Spectrum is a nice outdoor mall where you can wander around. They also have a carousel ($3/ride), train rides, and a ferris wheel. It's a nice place to lounge around, take the kids on some rides, do some shopping, and grab some food. Lots of good food there!

@su9su9: I like Balboa. Balboa Island is a small area with a cute tiny little downtown you can walk around. There is a candy shop and the place everyone goes for "balboa bars" which is an ice cream treat. Its got a little board walk you can go down but not too much else to do but what you can do from there is take the ferry (with or without your car) and that will drop you off in the Peninsula where the fun zone is. there is a ferris wheel, arcade and such. Something fun you can do there also is rent a duffy boat for an hour or two and cruise around newport. Like a pp said, check out groupon. They have duffy boat rentals on there all the time and you can fit a good number of people and bring your own food and drinks on it.