People always want advice on where to buy products cheaply, or the names of drop shipping companies. They want to start a business because they have read ads telling them how easy and profitable it is to start a drop shipping company. It seems they never get to the fine print that some actual hard work may be required to succeed.
The world is full of legitimate wholesalers that offer drop shipping services. Unfortunately, without knowing your product catagories you are interested in, it is impossible to recommend any at all. I would suggest using a search engine to begin your research into your niche. Narrow your search and look for specifics. Next I suggest you search for trade shows in your area of interest. There are trade shows held all over the world, and for all different product categories. Just about any product you could possibly be interested in, there is a trade show for it. If you attend a tradeshow, you will meet hundreds, if not thousands of manufacturers, wholesalers, and distributors, all in one place. You get catalogs, company information and contacts at a huge selection of companies.
There is no way you can place a value on having a face to face contact when it comes time to select products and negotiate prices. Some exhibitors drop ship, some only sell in quantity, but it is a great way to learn. I am a firm believer that knowledge and research are the keys to success when it comes to developing unique selling copy and marketing approaches.
Remember, you want to go into business to make money. To make the best use of your time and effort, you must sell unique products, or at least use unique approaches to selling your products, that makes you appear different than all of your competition.
I will add my usual disclaimer to my answer. Drop shipping costs you money. You pay for the convenience of having someone else pack and ship your orders for you. You pay for the convenience of not having to carry inventory or have warehouse space. You sacrifice customer service if the drop shipping company fails to ship on time. You have no control over the level of service you receive. These extra charges you pay means that it will be very difficult to make a good profit margin on your sales, because you will be competing with companies that import direct, or that buy larger quantities from a distributor and then ship from their own warehouse, usually at a more cost efficient way. Use drop shipping as a low cost no inventory commitment, way to test the market. Once you see sales patterns try and buy in quantity and ship by yourself.
Disclaimer # 2 I am a firm believer that the companies that want to charge you for access to lists of drop shippers, or access to their inventory, are poor investments for you to make. Companies like I have described will sell to anyone that wants to pay their fee. That means that the products they sell will be offered in just about all markets by many, many sellers. The competition will most likely, prevent you from making much of a profit and , again, the opportunity to make a profit is the entire name of the game.