You MUST book somewhere to eat beforehand. Went this year and the best man hadn't booked anywhere for the group to go. 14 drunken blokes looking for nosh on a sat night at 8pm. It was very tricky indeed, and we had to make several compromises. The groom went ape!
My only other suggestion would be not to look like you're a stag group, as some places won't be welcoming, though if the best man negotiates in advance with some f the big clubs and bars, often you can get guest listed or VIP entry. I went to Newcastle for an event once, and despite there being a large group, dressed as cavemen, we ended up getting VIP entry to two places, because the best man had booked ahead (by about 6 weeks) and made contacts with the venues (I think he had to commit to a certain spend though, but I can't imagine we didn't manage it, considering the size of some of the hangovers the next day!)
Enjoy!