Purchase a guide book for Israel. Recommendations include "Frommer's Israel" and "Lonely Planet Guide: Israel & the Palestinian Territories." See resources for more information.
Read the guide book and plan your itinerary, including how you will travel from one place to another. Book your accommodations in advance, using the information provided in the guide book.
Make sure your passport is valid for six months beyond your dates of travel, even if you are not planning to stay that long. According to the U.S. Department of State, Americans will also require a three-month tourist visa, which can be obtained at no charge when you arrive in Israel.
Purchase your plane tickets to and from Israel. If the ticket is issued as an e-ticket, print copies of your flight itinerary as you may be required to show this on arrival.
Print copies of a bank statement showing that you have sufficient funds for the duration of your planned stay in Israel. You may be required to show this to a customs official in Israel.
Order a small amount of New Shekel, the currency of Israel, from your bank before leaving. Most change shops in Israel will change U.S. dollars at bank rates with no commission, so it is not necessary to bring large denominations of local currency.
Pack according to the time of year you will visit. Israel is warm in summer and mild in winter, though nights in the desert or mountains can be cool year round. Dress tends to be casual, while remaining modest.