So you've found a supplier already? If not, it's really important that you are on good terms with your supplier - especially when you are talking about that amount of money. I would actually strongly recommend importing a smaller lot of something first, just so you get a bit more experience - even if it's just a box of stuff FedExed over.
It's a good idea to Google the supplier, just to see what feedback comes up on forums, if any. Plus you should ask them a lot of questions and get lots of pics.
You'll have to negotiate your trade terms - i.e FOB, CIF etc, and get yourself a Customs Broker.
The US business advice website has a lot of really useful information about importing:Link hidden: Login to view
The All Experts Import/Export forum can also be interesting, although it is UK-oriented. Link hidden: Login to view