Purdue University's School of Aeronautics and Astronautics recently released a feasibility study of Elon Musk's Mars colonization plan. I recommend a look at their full report and appendices if you have some time on your hands and an interest in colonization.
This was a student-run project in collaboration with Dr. Buzz Aldrin and Dr. Andy Aldrin, completed in a single semester. Given the time constraints and the scope of the project, the results are remarkable. While the final report could have used a good science editor's advice, look deeper. The underlying approach is sound, and there is a wealth of details on techniques for designing everything from a water tower to an interplanetary communications network.
At around 1,200 pages for the two primary documents, there is a lot of ground to cover. The entire end to end architecture for putting a million people on Mars within 100 years and keeping them alive is explored. I intend to write a series of posts addressing key points of the study in detail. I have not contacted any member of the team, so this is unsolicited and in no way meant to impugn their work. Their results are very impressive.