I went wedding dress shopping 3 times: once with just my maid of honour, once with my mom, bridesmaid and a friend and then finally by myself. I can tell you that it was fun having people there and I would recommend taking 3-5 people the first time. After that and once you have an idea of what you want only take one or two people that will be open and tell you the truth. I found that the other people I took just waited for my reaction and thoughts and didn't tell me what they actual thought. It was frustrating and annoying to the point where I went by myself and just picked one I loved.
Have fun with it though! Take your time and try on as many dresses as you want! And When you find the one you'll know