Drows are evil, so try to be evil! There are some good drow living on the surface but they’re very rare. If you want to play on the surface, better choose another race or play in the Underdark - you won’t regret it when done in the right way.
Spiders are sacred! (At least in Lolth controlled society) Never harm any spider.
Try to keep the social order in mind and greet adequately! If you’re a male drow, bow to any drow you encounter. If you’re a female, bow to at least any other female drow.
Learn some Drow words! It’s not that hard and you’ll encounter some basic words anyway. Just don’t use too many of them (almost anyone would understand pure drow sentences without a translator program or dictionary).
As a drow, choose the right pet/familiar! It’s your choice, but that evil drow magician with his small fluffy bunny doesn’t really fit into the Underdark. Spiders, bats, and rats are great companions!
In Lolth controlled cities there aren’t any male clerics! If you want, you can be one and follow one of the other drow gods but better keep it for yourself and present yourself as something different.
Druids don’t have any real place in drow society. You might become a temple guardian or something compareable but the Yath (priesthood) is reserved for female clerics only.
Never forget that this isn’t a single player game and every character has a real player behind him or her. As a female, treat males as you want, but don’t exaggerate.
You can use the following table as a basic vocabulary. If you encounter unknown words, just try to ask other players to learn them.
Drow English Remarks
Vendui’ Greetings If appropriate, add a title or name behind
Aluve’ Good bye If appropriate, add a title or name behind
Xas Yes Use the English or drow word - your choice
Nau No Use the English or drow word - your choice
Jabbuk Master Don’t say “Xas, master jabbuk.”
Llolth Lolth Just to distinguish both spellings