Miner
Your job is to simply Mine whatever you can get your hands and the more valuable it is the more money you get. You can also sell everything that you have gained.
Lumberjack
Your job is to simply chop all the trees you can find but don't forget to plant saplings as you get money for it and you have to re-plant all chopped down trees. You can then also sell your logs.
Fisherman
Spend your days out at see collecting fish and squids then selling them inland.
Farmer
Grow all your crops and animals then farm and kill them for money and food which can be sold.
Hunter
You get money for killing any animal you can find including all the dangerous mobs.