not sure which mode you're playing on.. I had to adjust for Hard Mode.. but the other two I went Science 2, Farming 2, Medicine2, Science3, Farming 3, then the other second levels, then Medicine 3 (or building if you calculate you have enought time to get medicine before they get elderly), then the others.
I get one baby around 6000 tech points, and end up around 12-16 kids by level 3 farming. Start of the game, 2 farmers, 2 researchers, one trainee doctor and one builder. Once food gets to about 600, I switch out one farmer to research, and the other farmer when it gets about 700, and just top up from time to time. The minute the doctor becomes adept, I put him sometimes to help build, sometimes to research... that's how I generally start.
Hard Mode I had to do Farming2 then Science2.. but the rest was pretty much the same.