In Israel, to get access to the web you need two types of service. Why two? Because one would just be too efficient. Basically, it would create a singularity and… nevermind. The first type of service you need is the infrastructure, which is the physical wire/connection to your house. The major companies for this are HOT (the cable company) and Bezeq (the phone company). The second type of service is the internet service provider (ISP) and you’ll pay this company to send data over their network to the internet at large. There are many ISPs, such as Netvision, Internet Zahav, orange, triple C, 018 xfone and others.

Note that Golan cell phone plans now include up to 20 gb of data per month, so you can use wireless tethering to your phone for pretty functional internet at any time.

More info:
NoFryers.com explains some newer ISPs and price tips
Megavolt.co explains more detail about the technical aspects of internet service
Nefesh B'Nefesh on setting up internet

Because much of the traffic has to be relayed back to the States, many websites are a little bit slower and thus it’s suggested to get a slightly faster connection - at least 5 Mbps - especially if you want to try to stream video. There are several packages to choose from and the liaisons can help you choose and call to get it set up. Total cost should be ~125 NIS/month or less.