You'll likely need PHP or ASP.NET to interact with their web service.
Basically with a web service, you do a specially formatted HTTP request to the service (usually as POST, but some use GET, PUT, etc). It'll then give you information back in a formatted way as well which you then have to parse using PHP, ASP.NET, etc.
Before going too in-depth in the specifics, you'll have to pick up and understand one of those languages (I recommend PHP) before you'll be able to really do anything with their web service.
Thanks - Currently this is all the information i have gotten from the software provider on the web services, and my main goal is to access the "add Order" service to automate imports from one eCommerce system into this.
Either should be about as difficult and/or easy. I personally prefer PHP. But like I said, you'll need to understand the language before you can use this web service properly (it won't be a case of where people can just give you a code snippet and that's all you need... it'll require some serious development).