BRIDESMAID AND BEST MAN ROLES

i got this from TheKnot:

Maid/matron/man of honor
The bride's right-hand for the duration of the planning process -- she's there to supply a second pair of eyes and provide emotional support as needed. In general, the maid of honor heads up the bridal shower and handles numerous wedding day details, which might include toasting the bride and groom, signing the marriage license, adjusting the bride's train at the altar, holding her bouquet during vows, and collecting gift envelopes at the reception. She also should help the bride get dressed, taking care to frequently remind her that she looks beautiful. She is the last bridesmaid to walk down the aisle before the bride, holding the groom's ring on her thumb.

Best man
This guy acts as groom's valet (personal aide and advisor) through all stages of wedding planning. He's a fashion consultant, bachelor-party master of ceremonies, and commander-in-chief of the groomsmen brigade. His duties include (but aren't limited to): getting the groom to the ceremony on time; giving the officiant his/her fee after the ceremony; signing the couple's marriage license; and holding the bride's ring at the altar. He also is famous for his toasting skills and dancing savoir faire.


Bridesmaids
Trustworthy gal pals and female family members who form the bride's entourage (and ostensibly work well together). They are a support team for the maid of honor, helping with pre-wedding tasks when asked (addressing invites, making shower favors, planning the bachelorette party, and more). Bridesmaids are often expected to hit the dance floor running and play surrogate hostesses to guests.

Groomsmen
A posse of male family and friends who assist the groom in planning and preparing for the big day. Their chief responsibility? To help the best man plan and pay for the bachelor party and to support the groom. It's also common to have groomsmen do double duty as ushers, leaving their posts in time to process with the rest of the bridal party. They also get to decorate the getaway car, dance with dateless ladies at the reception, and act as a resource for confused guests.

Junior bridesmaids/junior groomsmen/junior ushers
These are young members of the wedding party (aged 9-16). They'll attend all major functions (excluding X-rated ones) and fulfill the same responsibilities as senior squad members. Lasses can wear less-sexy versions of the bridesmaid dresses (if the dresses are risque); lads may don a tux like the big guys.

Ushers
Males (or females) who escort guests to their seats before the ceremony. Ushers are often employed in addition to groomsmen -- this way you can involve other important guys in the big day, including pre-teen relatives who may not have been up for planning a lascivious bachelor party.