Easy Money For Beginners:

Before you beat nugget bridge, make sure that you have a pokemon that really sucks, like lv4 weedle. use strong pokemon to beat the first five trainers. go back to the pokecenter and switch in all of your pokemon for the sucky one. go back and talk to the sixth guy at the end of the bridge. he gives you a nugget. then he challenges you. lose on purpose. go back and talk to him. each time you repeat this, he gives you a nugget. sell them for $5000 each.