Make your own Iron Daggers, It only takes 1 leather strips and 1 iron ingot. It gets your smithing up and you can unlock other smithing metals. Wear enchantments that can add onto your Smithing, you can wear 4 pieces in total which will make them 100% better (if your enchanting is at 100) Make sure you get the 2 skills per enchantment option in the skill tree.
Use conjuration with Bound Sword, Flame Antronach, get that up to a level where you can choose the Soul Trap on Bound Weapons so you can soul trap animals, etc. with empty soul gems. Use them to Enchant the daggers. I suggest using the petty gems as anything over that will not add onto extra coin. It can get maddening though.
Also work on your Speechcraft, items get sold for more the higher this skill is. (There is an exploit in Riften's Black Briar Meadery, you have to be level 25 in Speechcraft for it to trigger, talk to the guy behind the counter, ask him about Maven Black Briar, Bribe him, ask him again, then Persuade.. Keep asking and persuading. It takes some time but you'll be able to make some good coin that way, also wear enchantments that add to your Barter skill.
Plus just exploring caves, etc. will get you some good loot, the higher level you are the better the loot too.
I found the best companion in Riften, Mjoll the Lioness. I think you have to be level 15 or higher for her quest to trigger, it's a hard quest at a low level so be careful. Once completed ask her to join you, she never dies! Other companions die easy, all she does is go to one knee like she is a character that is necessary to one of the quest lines and gets up after a bit (or you can cast a healing spell on her). She can wear heavy armor, use two handed weapons and bows.
Get the Invest perk in the Speechcraft skill tree, go to the Riverwood Trader, invest in his business, he will have about 15,000 gold every 2 days to buy your higher end items.
When buying a house, try to stand next to a barrel, chest of drawers, etc. When you select buy house, quickly exit the dialogue, drop all your gold into the drawer, you will have the house and your gold too.