I started an import based company right out of University. It was perhaps the greatest learning experience of my life, so I might be able to provide some insight.
This part of your question causes me some concern:
> How do I start doing this? I just want to export/import large amounts of whole sale products, it doesn't really matter what the product is, but I don't know where to start.
The specific part that concerns me is that you say 'it doesn't really matter what the product is.' If I were you, I would start off by focusing on a general sector (if not one particular product). The problem with being too general is that you end up diluting your research time between a large number of different kinds of products. Starting an import/export company is about research.
> How do I get in contact with Chinese manufactures and people overseas? Are there any sites that I should check out in particular?
Alibaba is the 'correct' answer to your second question, but I will warn you - that site is full of con artists, so your research has to be spot on. A personal introduction from someone you completely trust is the absolute best way to get in contact with a manufacturer.