Things needed for a Mars colony:
1) Prefab habitat.
2) inflatable domes and atmospheric equipment for them.
3) manufacturing and mining equipment
4) Landers
5) mothership (storage and manufacturing area at first)
6) chemical processing equipment (to make hydroponics chemicals, air, and fuel)
7) robots (for heavy lifting, dangerous situations, etc.)

Crew needed:
1) Doctors (physical and psychological)
2) Maintenance/engineering (several)
3) Pilots
4) Biologists/agriculture specialists
5) computer/communications specialist (required on maintenance team, as we will rely on computers and communications for everything)
6) manufacturing specialist (also on maintenance team, as we will need to make everything)
7) would like a chemist (tweaking things to mars specifically, and making new things form local resources)