I usually move ony two or three turns max bofore I build my first city. If I don't find anything good, I have a tendancy to just restart.
IMHO the best early terrain bonuses are:
Whale- good mix of food/shield.
Wheat- great food for growing city.
Fish- good food off the bat, add a harbor...
then some other good ones for a little later...
Wine- build the mine and collect trade.
Gold- trade trade trade trade trade. A must have for the Super Science City. If you don't know what that is, look for it in the archives...you can get 600+ beakers in one city per turn! One magical time I got 2 in the same spot right off the start!
Try to get spots that have two, or three bonuses. they are by far the most important spots. Learn the shape of the city screen. And figure out the best spot to build and get all possible bonuses.