In SF1, mining gets you started since you can quickly return to Starport and sell them.
In SF2, mining is completely irrelevant. You have to sell your minerals to aliens, and those minerals will rot in your cargo holds waiting for a buyer. Selling lifeforms will get you started. Learning trade routes is fun.
EDIT - Oops - Were you asking how to gather minerals?
1. Orbit planet. Go to Captain. Select Land. Look for high ground and select a landing point.
2. Disembark. You are now in your terrain vehicle.
3. Check your map. Minerals will look like X's. Pick a direction if you cannot see any.
4. Park your terrain vehicle next to the pickaxe and shovel symbol.
5. Go to Cargo. Highlight the mineral and hit Enter to load.
It will be natural before you know it.
Post edited May 08, 2014 by KHHill91