I am a US Citizen and I am about to get married to an Australian Citizen. What is the best way for me to assist her to gain residency in the US. Should we marry in Australia (as planned) and then go from there or would it be better to marry in the US. We do not particularly want to spend anymore time apart.

K-1 visa and you get married in US.
Read here: http://www.uscis.gov/files/article/A2eng.pdf