I don't understand how people say smithing is a good way to make money. It's horrible for money. Maybe if there was a market for throwing knives but there isn't yet. You make way more profit for selling your ores than smithing them.
If you are planning on doing combat start with chickens. Fletchers will buy your feathers 10-15gp each. With 10k you can buy full mithril from shops (Plate varrock, legs Al-Kharid, Mith scimitar Al-Kharid / Addy long Varrock, Full helm Barbarian Village, Shield from Falador)
After chickens you can go to cows. Cowhides are decent money too. Going from 100gp each and even higher. After you get about 30 in all combat stats you can go to Hill Giants. Hillies drop herbs which can be sold for profit.
Mining and woodcutting are good sources of money. Fishing is currently worthless. Thieving seeds from stall in Draynor is good money.