What is involved in using the ServiceM8 API?

Hi, I would like to know what is involved in uploading a parts take-off list to serviceM8 using their API. In particular, once I am through their authentication, can I just send the list, or do I need to do a lot of back-and-forth calls to tie parts to their part numbers and suppliers and cost centres and all of that? Just how complex is it likely to be? I am wary of having to do a whole lot of processing before being abel to send the data.