The easiest and cheapest business to run is a home business with the Ticketron, then various entertainment and game items for the patrons to play with. You don't need to do a thing but keep the place clean to avoid the complaints. And you can maintain a job to build your skills and make money.
Stay away from restaurants until you feel pretty good about running a business. And have a lot of money, because it's pretty much a losing proposition to begin with.
Don't hire employees until you really need them. I've had my sim take care of the store alone until the business ranking is 4 or 5. Leave the prices at average. You'll get more sales than if it's you set the prices to expensive.
Go ahead and use the business rewards for the Cash for the first 2 or 3 awards if you need the cash, but switch to wholesale as soon as you can if you run a retail business. Remember though, if you only sale crafted items, wholesale does nothing to reduce your costs.
Electronics do real well when you have some cash to put into it. In fact as you upgrade home furnishings, rather than selling them in Buy Mode, open up a second hand shop or take them into your main retail shop and sell them for retail price
