Don't be afraid to ask prospective wedding vendors for a list of references. He or she should be able to give you a list of past clients that you can e-mail or call to ask them about their experiences working with the vendor.
It's important to ask references about their experience with the vendor, what services they hired the vendor for and if they were happy with the experience.
You will be spending a lot of money and time with the wedding vendors you hire so it's very important that you do your homework and research the businesses you are meeting with.
In addition to speaking with past clients, you can also ask the vendor to give you references for other vendors they have worked with.