I bot for 4 hours and have a 30 min break.
For steel bars you can make like 800 or so per hour. So 800 Coal & Iron.
I would advise a coal bag for the later levels, Mith, Addy and Rune.
As soon as you can, move onto the higher level bars. Youll make better profit/h, but will spend more/h on supplies. Spend more to Make more.
Rune ores are expensive and in high demand. So buy them on a separate account so when you can move onto them, you arent waiting for the supply's. Same for most of the ores.
I Suggest multiple accounts to maximize profit/h. I was running 5 bots doing addy bars before vacation and will continue when im home. Stamina pots are recommended so you don't lose run energy. Youll also need Cash in invent to pay the foreman up until i believe 60 Smithing.
Let me know if you need anything else :P