Mining helps increasing STR and VIT a lot. Saving the sulfur for spells to mainly attack types. Iron is used for making money, and can be used for crafting your own supplies of weapon and armor.
Starting out with just the stones by the guard towers is the best thing. Forget about the metal ore from now on. Mine stones and save them and sulfur. Sell the stones until you have 1000. you can get about 3k gold from it.
Starting with stone skill up to mining 75. buy mining mastery and then skill it up on the stone also to maybe 50. By doing so, you will be able to mine faster and more while your stamina will drop less.
Keep in mind that never mine or harvest anything outside of towns with an exception that your stamina drops below 25%. When you jump, you need some running sprinting stamina or fighting stamina.
