dad is first gen irish american, mom is second - norwegian american.
we were taught 2 basic rules.
1. never show up empty handed, anywhere, no matter what.
we normally bring wine AND italian or polish baked goods (since there's so many good bakeries of each around me), AND/or flowers.
every time i go to my parents, we bring veggies and herbs from the garden, as well as a few frozen meals i've prepared, so my mom can get a break from dinner for a coupla nights. same goes when we visit my siblings. it may seem weird, but they love my cooking. or so they say...lol?
even when i go to my buddy's house for monday night football, i bring a 12 pack and a pizza or two. neither goes to waste with my friends, and is always appreciated.
i remember we were having our monday night get together at one of the guys' house, who's wife was a bit iffy about what we might do to her place since she didn't know everyone. some of the guys are very large, very scary looking people.
i showed up early, with flowers and wine for her (i left the beer and pizza in the truck), and she seemed to relax a bit. especially after a glass or two of the wine.
not to mention how she kept trying to set me up with all of her friends. i was semi-single at the time.
anyway, it was a case that proved the theory. never show up empty handed.
2. everyone is always invited. period. all get togethers, from the biggest party to the simplest meal, no one is ever excluded. even strangers.
if it should so happen that you think you don't like someone, you'll be surprised at the friends you make, rather than the enemies you'll make by not including them. a little friendship and hospitality goes a long way.
my mom says that this is a norwegian practice from years ago. if you were having a get together, you'd place a lit candle or pot of oil in the front of the house as sort of an "open house" sign. anyone who passes by is invited in to the party, and to eat.