You will need to reach Guwahati. And then take a taxi or a hired vehicle from Guwahati to Kaziranga. Its a 3 to 3.5 hour trip. You can check the assam tourism website for Kaziranga. You can call on any of the numbers there. There are also a number of hotels advertised there. I would recommend Iora Resort, Borgos Resort or Agoratali Resort. If you call them you can arrange for a taxi or a vehicle from Guwahati to their resort. All three resorts would be in the main Kaziranga Area. They can also help you book your safari trips. You dont necessarily need to book your safari trips ahead of time as cars are always available.
This are the links that would provide you with all of the info :