What kind of network do you mean? Do you want to pull wired Ethernet into the bedrooms and living rooms or what? You have to know the total number of possible connections and how many wireless or wired connection there will be. Even my smartphone uses WIFI.
Sometimes WIFI will work just fine if the house is not too large. I have 2 computers in my basement, a desktop and another computer I use with my HDTV for streaming Internet Video, Youtube, etc. Then upstairs I have another computer with an AC centrino wireless card and it seems to do fine most of the time. I also have a tablet I use sometimes.
I started by getting my DSL service 2 levels up from the slowest level. I think that helped quite a bit. A little extra speed and a better wireless router or stronger antenna's on the wireless might help. Some wireless routers use dual channels and can handle more bandwidth. In some areas of the USA with higher population you might run into ISP's with higher net congestion which will slow you down. If that is the problem, improving a network will not help much.
I built my desktop for upstairs with a motherboard that has an "ac" wireless Centrino card. I did not really know if it would work or not until I tried it. If you have a basement with an open ceiling or drop ceiling with panels, you might be able to route a wired cable up through a closet and pop it out at the level of the baseboard near the closet door. You could also hire someone to put in wired connections that go to wall sockets. Just dont drill through an existing hot 110 wire. Of course you could pick a spot and drill through the foor.