Even though every lovely Swedish house Fru owns a sturdy cornbristle broom, this doesn't mean they actually like to use it so unless you wish to suffer a glare so 'icey' it'll freeze the warm cockles of your heart, do not,...and I mean DO NOT forget to remove your shoes upon entering the humble home of your favorite Swede. They don't like it,...they'll definately let you know about it,...and you'll feel like a silly, unrefined oaf for the rest of the evening.
If you go out during the night, do not forget to take your ID. In most of the clubs you have to be at least 21 or 23. In some clubs even 25.
Do not wear casual clothes. This might cause trouble, because the security which is everywhere in front of the entrances, might not like that.
Beware of drunken Swedes. During the week they are the nicest people on earth, but under the influence of alcohol.....