Coming to America

My family and I are considering spending a year or more living and working in the US. It is more for the experience than trying to profit from it and we plan on using somewhere as a base and travelling to see the country when we can, (long flights don’t phase us, we live in Perth & so are 5 hours from anywhere, Singapore is closer than some Australian cities).

I was looking for some suggestions as to where to base ourselves, what sort of casual/contract work is available for a Systems Administrator/Network Engineer type. What visas & work permits would we need?