You can rent a GPS or purchase a chip for your Garmin or other device to make it work in Israel. Some use Waze (an Israeli product) or Google Maps on their smartphones. (I now prefer Google Maps on my Samsung Galaxy S5.)
The problem, however, is that English-language GPS programs can be very confusing and cumbersome to use. The reason is language—while there is only one way to spell a city or a road in Hebrew, there may be a half-dozen ways to transliterate that into English. For example, is it “Caesarea” or “Kesaryia” or “Qesarya”? (Road signs use all three—and more.) When I entered an address on King David Street, one of Jerusalem’s major streets on which the King David Hotel, the YMCA, and all the rental car offices are located, nothing came up. When I entered “King,” I had a whole bunch of other streets, but not King David Street. When I entered just “David,” there was no “King David Street,” but “David ha-Melech Street” did turn up. Now, I speak Hebrew and happen to know that is how you say “King David” in Hebrew, but a non-Hebrew speaker would be flummoxed. So, unless you understand at least enough Hebrew to make educated guesses, I would use maps and certainly not pay extra for a GPS.