Windows 7: 3 ADSL Connection on 1 Network?

Ok here is the thing I have 3 ADSL lines that I want to connect to one network setup. I have read about load balancing and it seems hit and miss at the best of times so now what other solution should I be looking at here.

I am also wondering how the IP ranges should or could be setup for something like this. Just one idea that does spring to mind is have the IP ranges following on from each other. This now also brings to mind what about a default gateway I would think they would all need to be different but in their own IP range.

So I could have say some of the PC connecting through gateway 1 the next 2 and the other 3.

So any ideas on how to do this would be appreciated