You need a router and possibly a switch. The router will allow you to "share" your internet connection. Most will have a 4 or 8 port switch built in. To simplify the wiring a small switch can be added near the components if the router is not place near by. This would allow you to run 1 main cable from the router to the switch instead of 1 cable per device to the router.
On the brand side I am a Cisco guy but I would not recommend them for home use. Really the differences between the brands are minor. Your questions are pretty generic so minor performance differences aren't really an issue. Look into either a Linksys or D-Link router as they are the most popular. This is great if you have problems during setup because someone will likely have had the same problem. Most will have wifi and that is fine because you can turn it off if you don't want to use it.
On the brand side I am a Cisco guy but I would not recommend them for home use. Really the differences between the brands are minor. Your questions are pretty generic so minor performance differences aren't really an issue. Look into either a Linksys or D-Link router as they are the most popular. This is great if you have problems during setup because someone will likely have had the same problem. Most will have wifi and that is fine because you can turn it off if you don't want to use it.