Ill be travelling to greece in early september, wanted to spend a 3 days in athens and then on to mykonis , can you suggest how to get to mykonos & any suggestions you have on where to stay once we get there
Take a ferry, or fly.
Your options are to fly or take the ferry.
The flight itself is quick, but figure an hour to the airport, a couple for security and check-in, and then most of an hour on the plane, so ~5 hours?
For the ferry, you would need to get to Piraeus, probably most of an hour to get there and board, then depending on the ferry, 3-6 hours to Mykonos. Probably worth mentioning that ferries can cancel due to weather, but then so can planes (though more infrequently).
If the weather is nice, the ferry ride is a pleasant way to travel, for that distance.
You can also reach Mykonos by ferry from Rafina Port, located 20 minutes from Athens Airport.
There are ferries to Mykonos every day until 5:30/6:00 PM.
I'm assuming you have a good reason (and a large budget) for choosing Mykonos.
For lodging, I always suggest booking.com. You can use it just for research or book directly with booking.