What to wear?

the usual outfit for a wedding is formal or sometimes if the crowd is just simple & small semi-formal may do. guys usually be in tuxedos or suits or may sometimes just in longsleeves & tie w/ slacks if you're not part of the entourage. ladies should be in a formal dress or gown with some jewelries to match. if you know the crowd of the invited guests then it would be easy to pick an outfit 'coz you can imagine how this group or family calls for a party theme already.

Depends- assuming you are a girl. Is it black tie, casual, or semi-formal? You can usually tell this by the invitation, time of the ceremony and details of the reception. Age too determines what is acceptable. As well as what type of ceremony (religious or otherwise?). Safest bet for all- black dress that is long sleeved and at least knee length- pretty boring, but you didn't leave any other details.

Is it formal? I recently wrote a piece on just this. If it is just a regular wedding (in the afternoon) just buy a nice dress or pant suit that looks great on you and you are good to go :-) don't forget to buy a pressie :-)