Staying at the back can be worse; as the ride gets more people in it, the back has a rubber-band-y effect...it's always on the brakes, then pedal like crazy to close gaps. As such, I think it's more dangerous back there (but you get a heckuva workout). Best place to be is right at the front, first few rows; it is usually nice and smooth. Problem is, it can be hard to stay there, especially if there are a lot of hammerheads on the ride, because everyone else wants to be up front too. But usually on the flats the pace is manageable.
It might be worth hitting some smaller group rides with people who know what they're doing and who might be able to help point out some things to do and not do. The B ride may not always be the best venue for that, though if you ask and/or mention that you need some help, you might find some guys willing to give you some pointers.
Originally Posted by UmneyDurak
Most crashes happen when people panic and do stupid stuff.
I don't know about the actual statistics, but definitely, panicking seems to make bad things worse. But, if you don't know how to handle certain situations, you probably are going to panic 'cause you don't know any better. But it's not hard to learn what to do, and what not to do -- and people will help you if you ask.