You can also get a wire tester for $50 to figure it out. As for cost, if you have someone do it, costs are going to be everywhere, but a "typical" cost is $100 per "drop", which is an outlet for phone, data, or tv. That includes wire, jacks at either end, and maybe a patch panel and splitter for the catv. That will vary a lot depending on whether walls are "open" (i.e., no drywall up) or not and the size of the house, because wire isn't cheap. And if you put lots of jacks in one location that can save something (e.g., at each location you have one phone, one data, one catv).

Lynn, I now see more clearly what you're trying to do. It's much like setting up a network at home. When you're sharing internet with 2 or 3 computers, you'd be setting up a router (such as a Linksys) with wireless capability. First you'd need to setup the router with an encryption. The manual for Linksys has good instruction on how to set it up. This will only allows computers that share the same encryption number to be within the network and will keep the others away. The nearby computers will see the Linksys ID but will not be able to get into the network without the encryption number. Since you're the owner, you have the choice of who to give that encryption number to once you had it set up. This number can be changed at anytime you feel a threaten nearby. I normally use the Linksys auto encryption number because it uses a lengthy combination of letters (case sensitive) and numbers which makes it difficult to hack into. What Jane explained only works if you're not setting up a network. When you set up a network, regardless of whether you're using wireless or a cable, all 3 computers can still be seen if allowed to. Each individual computer within the same network can be set up so not to allow other computers to see it. The only thing they could see is a list of computer's name within the network. Windows have a network security feature in the Control Panel that allows you to set up what you want to share and what not. For example, all 3 of you may want to share the same printer and nothing else. As far as hacking, by setting up an uncrypted router (hardware firewall), you should be pretty safe. Plus, each individual computer should also have a firewall software installed. This is the 2nd protection. A professional hackar (or whatever you call him/her) would probably not interest in your type of business to go through the trouble of hacking into your network. Think of it as your home have an alarm system but your neighbor doesn't. Guess, which home the burglar would rather break into? As for within the network, if all 3 of you trust each others enough to share the cost of internet service, I don't see a reason for worrying with one of you hacking the other one's computer. Do you? If you do however, then, it's best not to share the internet service. You may want to set up a rule to let each others know right away when one of the computer is stolen. If that ever happens, change the encryption code right away to prevent the stolen computer entering into your network. Keep in mind that the your friend's computer won't be able neither until you provide them with the new code. Someone already mentioned, it's best to always set up a password and 'lock up' (not log off) the system whenever you're walking away from it for a few minutes. I know you probably already know some of these things. I just add the info in for other readers that may need it.

rmverb - agreed. I did sort of a hybrid of that - I planned and laid out the low voltage locations and types, and paid my electrician to actually run the wire (which I purchased as well to make sure it was quality) in the walls. Once the sheetrock and paint are up I'll terminate everything on both ends (they have tools now which make this rather easy). It'll take him 2 days, which means it would take me 4 - and I just don't have the time or interest in that. My DIY time can be spent much better - both economically and enjoyment wise. If you don't mind my asking, how much are you paying per drop? I have about 40 drops, and with the cost of wire, boxes, plates, etc. It'll end up around $1600, or $40 per drop. I saw from other posts that new development builders charge around $100 (though of course that includes termination).

One thing I would add to Square Peg's advice is that more WAPs (wireless access points) is not always better. You want to make sure you add enough WAPs so that anywhere in your home there will be a dominant WAP signal your device will want to connect to. However, if you have 2 or more dominant signals coming from different WAPs your device might not jump correctly from WAP to WAP as you walk through your home and a sluggish/inconsistent Wifi connection will result. Also make sure you adjust your WAP wireless channels correctly so they do not overlap. Download a free Wi-fi scanner app so that you can view competing wireless devices from neighbors and make adjustments to your channels accordingly so you are where they are not. If you are in a large condo complex or down by the beach you are pretty much screwed as far as potential wireless interference is concerned, but in other less populated areas scanning for less populated channels is a good idea to optimize Wifi performance. Generally alternating Channels 1, 6 and 11 for the 2.4Ghz wireless radio is the way you want to go barring any specific exceptions. If you are installing Zigbee based devices, stay away from Channel 11 on the 2.4Ghz Wireless radio as many Zigbee devices default to Zigbee Channel 26 which can interfere with it. Generally keep Zigbee devices at least 6ft away from Wifi devices if you can help it. Safe bets for lighting are Lutron's Caseta or RA2 which communicate on the 1.9Ghz spectrum and any Z-wave devices which operate on the 900Mhz spectrum.