I actually got my start on the Web writing about how to share an Internet connection. At the time (back in 1999 or so), consumer-grade routers weren't available, so you had to set up one computer as your Internet sharing machine and install Wingate, Sygate or one of the other programs available at the time.
The Internet has changed a lot since then and there are dozens of inexpensive hardware routers to choose from. Hell, you can even pick up a router in a blister-pack at your local Costco if you want to! But how do you know that it will the do the job?
Many people choose a router from a friend or colleague's recommendation or simply buy what's touted as the most popular product by the shopping website that they like to use. If your needs are simple, you'll probably do just fine with this method. But if you use the Internet in more advanced ways, you'll need to do some homework in order to end up with a product that you'll be happy with.
The first thing you need to know is how fast your Internet connection is. In the U.S., download speeds are slowly creeping upward, but there are plenty of connections (mine included!) that run at under 2 Mbps downlink and about a fourth of that (~512 Kbps) for uplink. If you fall into that category, most any router on the market today will handle the full speed that you're buying and not slow you down.
The next speed tier is around 5 Mbps downlink and most current-generation routers will handle that, too.
If you have ADSL2 service, your downlink speed will be 10-12 Mbps and you'll need to start to consult our Router Charts for products that can handle the speed. Most current-generation designs will, but it's better to be sure.
The next step up is ADSL2+ service, which can clock in above 20 Mbps. So you'll definitely need to check the charts, since some of the less-expensive routers won't handle these speeds.
Finally, if you're one of the lucky few to be able to get Fiber-based service (AT&T U-Verse, Verizon FIOS), your top download speed could run as high as 50 Mbps. Once again, hit the charts to find routers that can handle the speed.
NOTE: When using the Router Charts, make sure you use the Benchmark Selector (Figure 1) up at the top of the chart to check the WAN to LAN, LAN to WAN and Total Simultaneous Throughput charts. While most products have very similar up and downlink speed, some don't. So check to be sure!
Figure 1: Router Chart Benchmark Selector
Chances are that you'll find that most routers will be fast enough for your needs. So your selection will be more based on the features they provide. Let's look at some profiles of different types of Internet use and the features that a router needs to be able to handle them.