not sure what you mean by distributing the two lines, do you mean bond the lines together for high avalability and or more bandwidth, if so some of the zytel modes support this (i have one here) you basically hook one up to each line then designate one as a secondary link and set it up on the primarys web based setup page, this gets you high availability but not load balancing
as for cabeling, cat5 is the way to go, if you want gigabit and you have long runs then you may need cat 6 but most of the time cat5 is pasable (you can test it by laying it down before hand
so to sum up you need:
Cabel (cat5)
wall jacks for said cabel
a switch
a router
a modem (or two)
note that the switch, modem and router can be combined into the one item (like the linksys boxes), the plus with these is that they have basic filtering, if you need something better then you could replace the router with a linux boxes and one of the security distros, they are point and click these days (over a web interface) but its a good idea to have a firm understanding in networking and linux beforehand
anyway to answer the originol question about distributing the 2 broadband connections, once you have them sorted out about how they will talk to eachother and do what you want (HA or load balence) then thats it, you iwll only need the one jack to each room and the switch/router will take care of all the multiplexing of the data to the right line
btw, do you need 2 lines? if so of what type are they