I've personally never had trouble interacting with guys, in my experience there are actually fewer social 'rules' with guys than with girls, and it's more okay if you accidentally offend someone.
This probably depends on what type of guys you're trying to talk to, but usually you can tell how a person wants to talk within a few minutes...so just be yourself. You don't have to worry so much about whether you're following some big invisible set of rules, everyone is probably too busy thinking about how they are portraying themselves to think too deeply on what you're doing.
