Agreed with the general consensus. Basically:
- Play in the right division. Most good beer leagues in places where hockey is popular will have many divisions, ranging from newbies in the bottom levels to plenty of ex-CHL/college players in the top level. My beer league in Vancouver has 13 divisions I think (each with about 7-10 teams), if you and your buddies played high school and/or low level travel hockey I'd say you guys would be roughly a division 6/7 player in this league, in the right division you won't have to worry about your buddies hot dogging because they simply won't be able to without turning the puck over. I used to play high school hockey in Toronto (and am still in my mid 20s), my team is in div 7, and I'm an average player in this division
- As long as you're in the right division, absolutely play as hard as you want, kill yourself on every shift just as you would in minor/HS hockey. Beer league is more casual than what you've been playing, but it's not shinny or anything, your teammates and opponents will expect you to skate hard. Just make sure to keep it clean, don't chirp/be obnoxious, and remember that it's non contact (minor bumping and pushing is fine, especially if someone is screening your goalie, real hitting is not OK, neither is dirty stickwork). Some guys think they are "agitators" in beer league, these are normally guys with no talent who spend too much time listening to analysts on TV talking about how effective Steve Ott is, don't be "that guy"
- The only exception to "play hard" is in major blow outs, or if you're way too good for the division you're playing in. Easily remedied by just playing in the right division, or ratcheting down the intensity slightly if your team is really smoking the other team. If you're way too good for your division, just focus on passing and don't go quite as hard, but obviously you'll have way more fun against similarly skilled opponents, where you can go all out
- Fights are very rare, I would say never start a fight in beer league under any circumstances, defend yourself if need be but this should almost never happen
That's really it. As for celebrating goals, as long as it's a close game then congrats with teammates (high 5s) is always cool, maybe even a touch more for big goals (OT winner in the playoffs or really any hard fought game), just don't go over the top, no Radulov/Ovy type celebrations.