I'm not as advanced as you guys, but today I started a new career and finally worked out how to read Kerbal Engineer Redux to calculate dV. So, I built a rocket to take Jeb into Kerbin's first orbit, only to realise maneuver nodes aren't available yet, so I had to perform a very improvised re-entry with little fuel. After that, I grinded some part missions, and now I'm pretty much bankrupt and stuck with just 4000 funds. I guess a new career will be started tomorrow