Here are some traditional guidelines on who's supposed to pay.
Ceremony
Bride and family pay for church, synagogue, sexton, organist, etc.
Groom and family pay for marriage license and officiant's fee.
Clothes
Bride and family pay for bride's dress, veil, accessories, and trousseau.
All attendants pay for their own clothing (including shoes).
Flowers
Bride and family pay for arrangements for the ceremony and reception, plus bouquets and corsages for bridesmaids and flower girls.
Groom and family pay for bride's bouquet, boutonnieres for men, and corsages for mothers and grandmothers.
Bride and family pay for wedding photos and video.
Pre-wedding Parties
Groom's family plans and hosts the rehearsal dinner.
Bride plans and hosts bridesmaids' luncheon.
Groom hosts and plans bachelors' dinner.
Maid of honor and bridesmaids host shower.
Best man and ushers host bachelor party.
Reception
Bride and family pay for all professional services, including food, drink, decorations, and music.
Rings
Bride and/or her family pay for groom's ring.
Groom and/or his family pay for both of the bride's rings.
Stationery
Bride and her family pay for invitations, announcements, and wedding programs.
Transportation
Bride and her family pay for transportation of the bridal party to and from the ceremony and reception.