There are additional pages that discuss specific things you might want to do onthe internet, including:
The first step in deciding on your approach for network access is to consider what you want to do with the network, how often you require access, how fast you need the network to be, you ant to do it, and how much you are willing to pay.
The cable companies have recently been increasing the available speed on their system to better compete with the DSL offering from the phone companies, and in most major cities I would recomend choosing a cable modem. However, if you do not have cable television, you may find the DSL offerings from your telephone provider to be less expensive, and they will still provide plenty of speed for most uses.
When wired connections are not available, or when mobile access is required, some choose to go with wirless network access providers. More information on using technogies like satellite, 3g and 4g phones, Wimax, and Wi-Fi for the connection to the home can be found at Wireless Internet.Org.
If you will have multiple computers using the network at the same time, if you want wireless access when using your laptop in your house, or if you have other network devices to connect (such as a network printer), you will need to set up a more elaborate local network. Such a network can be used to allow the sharing of printers, scanners, faxes, and files among the systems on your local network. This interconnection also makes these resources more vulnerable to compromise if any of the systems on your network become infected by viruses or worms, or if someone manages to break into your system through the wireless connection or your router, which is why it is important to set up firewalls and other defense measures described at the bottom of this page.
Some cable modem and DSL providers offer to lease you the wired or wirless router needed to provide acces to multiple computers but they will charge extra to do so. You can also purchase a router yourself, connect it to your cable or DSL modem, and once configured, you will be able to connect to the internet from any of the computers on your internal network. Note that the terms of some cable modem and DSL services limit use to one computer at a time unless you pay for an enhanced level of service, so to keep within the terms of your agreement you should determine if this limitation applies and subscribe at the appropriate level of service for your actual use. Most of the routers you can purchase provide "network address translation", which means that from the outside, it will look like all of your computers are a single computer - i.e. connections will be from a single internet address.
Additionally, it is extremely important that you set up wireless security on your routers. Without this, your neighbors, or anyone driving by your house will be able to access your home network, possibly connect to and read data from your computers, and use your network connection. If they reach the internet through your open wirless connection, from the outside it will look like you are the one connecting and you could be blamed for whatever they do.
Of the configuration options for wireless security, I recommend one of the WPA options, but depending on configuration of the wirless devices you will use (e.g. you have an old wirless card or software on your laptop), you may have to settle for WEP. While better than nothing, WEP security has been broken, and will not withstand an attempt by someone that knows how. The main security benefit of WEP is that it will prevent inadvertant connection to your network by your neighbors. WPA is better, but it is important to note that it only protects your data in-transit on the wireless network and it doesn't prevent discovery of data by other users on your network. Thus, in addition to the wirless security mechanisms you employ, you should also use SSL or TLS for web connections, tools like SSH for connections to remote computer systems, a virtual private network to connect to your main office, and email encryption tools like PGP or S/MIME to protect email communications.
Such a firewall will limit some kinds of attacks, but not all. In particular, as long as it is configured properly, the firewall is effective at blocking in-bound attempts to compromise your systems.
A firwall does not block all attacks; in particular it will not block viruses received through e-mail or from the web since these infections reach your system when you make an out-bound connection to view a web page or to download e-mail.. Once your system is infected, a firwall will usually not be effective at protecting your system or network, since the damage caused (recording and sending password, sending spam for others as if it originated from your system, launcing denial of service attacks on other parts of the Internet) by such virues originates inside your network.
For this reason, it is extemeley critical that you also install and maintain appropriate anti-virus, anti-spyware, and other security tools, and you should consider turning your system off when you are not using it.