Czech Travel with kids

http://www.livingprague.com/kids.htm
sorry I have never travelled with children do not much of a help but the link above will give you a lot of info,the guy that runs it has 3 kids of his own but I think the youngest will be a teenager now.
he also does tours in the city that might be fun for the family

Thank you for the information! I've found a few locations for restaurants, lodging and activities, but if anyone has any additional suggestions (specifically outside of Prague), that would be great! Thank you again for the information.

Hi warren. Just curious about your route. You are considering flying into Prague, travelling through parts of CR to Graz then travelling all the way back to Prague to fly home. Perhaps look at flying open jaw; into Prague and out of Vienna after Graz.

EDIT: I misunderstood your routing. On a second reading of your plans I would suggest flying into Vienna, visit Graz, then onto Cesky Krumlov (or other CR locales to be determined), ending in Prague. Same idea though; open jaw into Vienna, out of Prague.

Certain areas will be flooded with tourists even in May. Among them Prague and Cesky Krumlov. IMHO 4 year old kid couldn't care less if he is in Prague or Cesky Krumlov. (S)he will care if (s)he has something or somebody to play with. If your kid likes water then there is a huge and modern aqua park in Pasohlavky. Most kids like it. On your way from Prague to Graz get off train in Brno and take a bus to Pasohlavky (less than one hour - maybe half an hour). You can get accommodation there, too.

Thank you for your suggestions! Completely agree the feedback that toddler won't really care what he sees as he'll be just as happy with riding in a train all day as much as anything else. Ideally, we end up with a shared experience balancing what my wife and I will enjoy as well as our toddler. Looking into the suggestions that others provided in the forum, Petrin Hill seems to be a good location to visit for both adults and kids; along with potentially attending a marionette performance in Prague if there is a performance that caters towards kids during our stay. I very much appreciate the suggestion of Pasohlavky as this was a location that I hadn't considered yet, and I will look into Brno a little more as well for a location outside of Prague.
We'll definitely consider the open jaw flights, especially if we don't circle back to Czech Republic/Cesky Krumlov after Graz. Regarding the itinerary, I will be based in Prague for some time prior to my wife and toddler coming from the states so thought it made sense to start in Prague before traveling to Graz. The Graz portion of the trip will likely hit in the middle as we are visiting friends over a weekend. From there, I was considering circling back to Prague to be able to spend more time outside of Prague in Czech Republic while saving a bit on flight costs with a roundtrip ticket. The entire trip will be 10-14 days so was thinking to spend 3-4 nights in Prague, 3-4 nights with our friends in Graz, along with 3 nights in another Czech location before circling back to Prague (initially thinking of Cesky Krumlov as a home base for those 3 nights). We do like to get a feel of the culture of the country when we travel, especially visiting with the people that live there so we would be happy with a farmhouse stay or something that may have easy access to nature trails or something of that nature in lieu of a heavy tourist destination. Maybe Telc or Pavlov as an alternative location to Cesky Krumlov?

This was a long post so if you made it this far, thanks for sticking with me!

Yes, open jaw is another possibility although your original idea of a circle was not bad either, considering that round trip is usually (not always) cheaper than open jaw. And you would not have to skip Cesky Krumlov which is a gem. You can substitute with Telc or Pavlov but while beautiful they are not in the same category as Cesky Krumlov (that's why there are mobs there and not so much in Telc and even less in Pavlov). If you go to Pasohlavky then Pavlov is on your way to Mikulov (worth visiting) and Vienna. We stayed in Pavlov in Pension Florian and had nice view of Divci Hrady (Girls Castle) on Palava Hills. With a little imagination you can think that you are in Tuscany. There are marked trails on Palava Hills. Easy hikes from Pavlov. It's arguably the best wine area in C.R. If you are into wine then visit salon vin in Valtice. http://www.salonvin.cz You can switch it to English. Nice chateau, lakes and minaret in nearby Lednice.
Petrin Hill in Prague is a good location. Go to Mirror Labyrinth - kids like it. And also you can go for views up to Petrin Tower. It was built like a smaller copy of Eiffel Tower.

Thank you Ilja for the continued feedback. This was very helpful, and very much appreciate the feedback and recommendations on Pavlov. We are not wine drinkers, but the location does look like it could be a good alternative to Cesky Krumlov or maybe adjusting our trip to add a couple nights to our trip since we do have some flexibility. A relaxing area with good views that our toddler has some open space to walk or climb around sounds lovely right now.

http://www.dpp.cz/en/nostalgic-tram-line-no-91/
whilst in Prague a nice very cheap and fun weekend activity for the kids (and adults) is the Nostalgic tram, only runs at weekends but really costs pennies and is good fun ,will fill a couple of hours and let you see a fair bit of the city including areas you might not have even considered.

There are some great castles not far from Prague. When my son was quite a bit younger we visited Konopiste and he loved it! There is a deer park and bears in the moat of the castle! When we were there they had a bird of prey exhibit with about 30 eagles, owls, etc. that you could get right up to and watch...beautiful! You can also try shooting a bow and arrow in the moat (in another section away from the bears!). I think your 4 year old might even like the interior...it was used for a while as a hunting lodge and many of the hallways are completely covered with thousands of trophies of game from all over the world, each one meticulously labeled and mounted. There is also an armory room that is something to see.
You can rent little paddle boats on the Vltva Rive in Prague right in the main part of town south of the Charles Bridge. Many different kinds to choose from!
Cesky Krumlov has a river running in a circle around the town...you can rent kayaks or canoes and take a loop around the town. There are bears in the moat of the castle here too! Apparently that's a thing in the CR.
This little article makes some great suggestions of things to do with kids depending on where you plan to go in the country.
Enjoy your trip! The Czech Republic is one of our favorite countries in Europe...it's beautiful, cheap, and full of things to do and see!

Thank you for the additional suggestions! These are all great ideas.