The first thing you need to do to be successful in Village Sim is to discover another source of food. The berry bush will only feed your villagers for awhile, and they need to learn to grow their own crops. Most people have found that it's necessary to research Level 2 of Harvesting as soon as possible, so that the villagers can learn to farm before they run out of berries. You should put off exploring other parts of the game until you have the food supply taken care of. Most of the puzzles that you're stuck on will be solved by researching more village technologies.

You should have a look at some of the other threads that contain tips and hints on the strategies that people are using.