100 Mbps Network Limitatiom

I have 2 qestion about 100 Mbps Fast Ethernt..
1- What is the rule for connecting Hubs? How many hubs used in this network? Only Two Hubs? What I do if I want to expand my network?
2- Can I connect the Cat5 UTP cable as follows

1——-3
2——-6

3——-1
6——-2

and cut the other lines (4,5,7 & 8)?