Two words, Welcome! And, research. Research is your friend. Research everything you can think of, from the product you want, to the validity and legitimacy of the companies you want to deal with. Another peice of advice, think outside of the box friend, not to say Ipods are bad in any way, its just that the easiest way to make money with them has been saturated by the market already, so if you want to do them, remember to approach it in a different way.
The art of war says, If they are big and you are small, they are slow and your mobile. Find another way to attack the problem to get a solution. Ebay is one of many sites. If you have a greensheet I bet advertising there would be wonderful.
Two last final tid bits. Ask Ask Ask. Ask quesitons till your brain pops. It could mean the difference between great profit and great loss. Finally, for Ipods, you want to ask if they are new in box from apple, with the apple one year warranty. OEM is a way of them saying its not 100% legit. Go for USA warranty, not international warranty, and it must be the Apple one year. **edit Also make sure the serials match from box and product!! I remember on dhgate one of them saying the serials on the box and the product were different.