transportation advice to travel from CDG to Rouen

Go to www.oui.sncf for tickets.
Your departure station is: paris aéroport roissy charles-de-gaulle.
It will take about 5 hours and cost around 60€ to 70€ each way if you purchase tickets quickly.

The sooner you purchase tickets, the less you will pay.

Actually, there aren't any trains that go straight from CDG to Rouen: you first need to head to Paris Saint Lazare station. From there it's a 1.15 hour train ride that costs 27 euros each way on the spot and between 10-20 in advance.

To get to Paris Saint Lazare from CDG, you either take a taxi for 50 euros flat fare, or take the RER B to Gare du Nord where you change to the RER E to Haussmann Saint Lazare (which connects to the mainline trains at Paris Saint Lazare), for 10 euros per person, but not great with a lot of luggage (there are escalators, but little space for luggage on the trains). Journey time is about an hour (a bit less by taxi if you're lucky), but give yourself some buffer if you have a specific train to catch.

I think you should go to Gare St Lazare in Paris and take a train from there. There is no direct train from CDG to Rouen. You will waste time going on a train from CDG. The trip from Paris can be as short as 71 minutes so even with the trip to Paris, it will be quicker and probably with fewer connections.

Maybe hiring a driver would be quicker and easier than the multiple train idea. Approximately what should that cost us to travel from The Sheridan hotel/CDG to Rouen? I think it is a two hour drive? Thank you.

As mentioned, you need to get from CDG to Gare Saint-Lazare. Depending on the number of people, either take a taxi for €50 (for up to four people), or the RoissyBus for €12 per person that goes straight from the airport to the Opera Garnier (7-minute walk to the train). Taking the RER and metro with luggage on stairs and sometimes escalators is crazy. With all due respect, only people who get their information solely form Rick Steves' books or who haven't been by any other method recommend that. The bus is simple, cheap, has no steps (other than one to get on the bus), and doesn't tunnel underground.

To estimate the cost of a private driver, map out the route use Google Maps to see how many kilometers the trip will be. Then take the number of kilometers and multiply it by 1.12. That will be the lowest estimate and,ost likely it will be double that because the driver will want payment to co er the time to drive there and the time to return to Paris.
@PharmerPhil, I beg to differ with your conclusion about people who suggest the RER for the trip from CDG to Gare St Lazare. Like you, I take either a taxi or the bus for that trip, but I don’t think one should make generalizations about people who suggest the RER. After all, it is generally faster than the bus.

Roissybus is, indeed, an option that I tend to forget about, but it does require some (easy) navigation to get from the bus stop alongside the Opera house to the St Lazare train concourse, half a mile away. And it's more 10-15 minutes than 7, given the typical pedestrian density in the area. To me it's a tie with the RER.

Take taxi to Gare St Lazare in Paris - from
Cdg price is only 50 euros ( it is a set price not meter so don’t let anyone tell you different !)

Then take train - short ride - I visited Rouen as a daytrip from Paris a feed ago , lovely .

The blog Paris by Train provides photo tours of major train terminal, which can help newcomers orient themselves.

https://parisbytrain.com/gare-saint-lazare-train-station-photo-guide/

We took this journey yesterday. On the advice of an information person at CDG RER B kiosk, we took the train to the Chatelet stop, transferred to the #14 train (purple line) to St Lazare and caught the train to Rouen. Chatelet is the stop after Gard Nord.

I heard there was a BUS from CDG to Rouen for around 10 euro per person. That sounds good to me. Why is there no bus service listed in Rick Steves Normandy book for Rouen??

Yes, there is Flixbus on the route I believe, but the buses aren't that frequent - and traffic delays are frequent. Feel free to try them, and report back!