Time from airplane arrival to hotel in Prague

Immigration (entry into the EU - show your passports) is the variable no one can predict - could be 5 min could be 50 min, at any airport, depending on how many flights landed when you did, how busy they are at that time. "Customs" is a 5 second walk without stopping past customs agents as you exit baggage claim for most people, unless they have something to declare.

Taxi from the airport to some hotel in the center? I'd guess 25-35 min. Check a Google Map and enter in your specific hotel to get an estimate. By public transit? Bus + subway connection, probably about an hour, last as I recall.

And of course the flight might be late (though I've been quite lucky on that score).

as far as I am aware you will enter through terminal 1 which is the terminal I use all the time travelling to and from Prague.,even at the furthest point it is not far to the passport control and longest I have ever had to wait is about 5 minutes, might be a bit longer as you will have to go though the non EU queue, baggage is usually through quickly and on a couple of occasion it has arrive just as I got through passport control.Depending where you are staying in the city a taxi/shuttle will take 30-45 minutes and you are going to be arriving during rush hour so expect the latter. by public transport about the same time.
so from arrival to city centre, possible within an hour more likely 90 minutes to 2 hours at the outside.

http://www.praguetransport.com/
if you are looking for a private shuttle to get you to your hotel I can recommend this company,actually run by an American and his Czech wife, I have used them numerous times as have family and friends.

Unclegus, thank you for the recommendation, I was already looking into getting them. I figured when all was said and done I would be at the hotel in the city center by 9:00 a.m. so that seems about right from what everyone is saying. It's a great time to arrive I just hope we're not too jetlagged to take advantage of the early start.

when I travel to Prague I usually have to get a 6.00am flight so means getting up at 2.30 am to get ready to go to the airport so I am often in the city by 10.00am not jet lagged but certainly tired.

If you're planning to get into your room on arrival at 9am, you might want to check on that. Rooms are not typically available until mid afternoon. You can likely store your bags at the hotel though. If you need to get into your room that early, just book the room for the night before you arrive and you can check in right when you arrive.

https://www.youtube.com/watch?v=ZgLGVQ6RzZg
you might like this video,looks like they are starting from T2 .

Thanks Unclegus, I'm gonna have to look and see if there is a similar video out of the international non Schengen terminal.

I use the non shengen terminal (T1) and I would reckon it is much the same as that video possibly shorter but T1 has 2 wings A&B , B is closer to the passport control area.