If your looking to sell hard good types of products on the internet, then you need to find merchandise.
There are a number of ways you can find products to sell on the internet. You can find wholesalers and purchase stock, you can make them yourself, you can find others in your area that make them, you can find others in your area that will let you work off their inventory, you can find companies that will drop ship for you to your customers.
The ability to make your site profitable and at the same time keep overhead down is if you can avoid the purchase stock. If you do not have to stock a product you can run your online store for next to nothing in terms of overhead.
If you can make the items yourself, you do not have to produce anything until orders come in. If you can find others in your area who already make or stock merchandise you can probably work out something with them so that you can sell them online and get a commission, if your able to find a company that will give you a wholesale or reseller account and drop ship for you again you do not have to invest in stocking merchandise.
The biggest plus in online selling is unlike a bricks and mortar store you do not have to stock anything to sell something. You only have to be able to get it within a certain period of time, as defined in your website.
So now that you know what you want to sell you need to find the cheapest way to obtain stock. As I stated earlier the cheapest way to get into business is to start out with something you can make or get from somone quickly when an order is placed or the drop ship method, which I personally like and use frequently. This allows you to start your business without the overhead of a Bricks and Motar type of retail operation.
Sparky