I have been involved in the dropshipping industry for quite a few years now, and I have come up with a pretty good list of things that people don't know, don't realize, or are confused when it comes to dropshipping.  Here they are:

1. It's not as "easy" as people make it out to be.  You are starting a real business, even though its online you still have to go through a lot of the same steps and frustrations of an off line business.
2. Not all companies that say they are a dropshipper really are.
3. Not all dropshipping companies/lists that say they are a real dropshipping company/lists really are.  (Just check to see if they are in good standing with the BBB - like The Shipper)
4. You need a business name and Tax ID to work with a legitimate dropshipping company.  Doing so is going to give you real prices to products that you can sell and actually make money online.  Getting access to companies or lists that do not require this information from a home business owner is just silly, and they are playing you and will take your money, and you will never make any money from any such company.  Why?  Because they are giving you no profit margin.  Look the prices they are giving you and compare them to Wal-mart; do you see any difference?  If so you are probably seeing that Wal-mart is cheaper.  Good luck with that!
5. It takes time to make money.  If you are starting a website, you must establish yourself with the search engines.  Overnight success 99% of the time is not achieved on the search engines.
6. After establishing yourself with a dropshipping company, your relationship is not set is stone.  You can negotiate with them later on once you have established yourself with an online presence.  If you like you can move on to someone that will be giving you better prices.
7. Some dropshipping companies that you set up a relationship with do require an application fee.  They have paperwork to tend every time someone signs up with them.  Thats takes time and money.  It is a normal thing to work with some suppliers that do require this fee.
8. A lot of dropshipping companies have a drop ship fee.  The best solution is to just add the dropship fee into the cost of goods, and not make the customer figure out how much the product is going to cost after tax, shipping and dropship fee.
9. You must be prepared for returns.  99% of the time when customers return something it is not the problem of the dropshipping company who sold that product to you.  So be prepared for returns and give yourself a cushion of money for such occasions.
10. You can work with as many different dropshipping companies (at the same time) as you like.
11. Some dropshipping companies do not allow you to sell their products on places like eBay or Amazon.

This should be a pretty good list for the newbie to dropshipping to gain a better understanding of what to expect.  If anyone has anything to add to the list I would love to see it?