Left to Right:
Shindong- lead dancer, lead rapper, choreographer; 6th oldest
Kangin- 5th oldest
Yesung- main lead vocal; 4th oldest
Sungmin- lead vocal; 7th oldest
Kyuhyun- lead vocal; youngest
Donghae- lead dancer; 5th youngest or 9th oldest (in reality is younger than Siwon)
Kibum- lead rapper; 2nd youngest
Hankyung- lead dancer; 3rd oldest (Chinese member)
Heechul- 2nd oldest
Eunhyuk- main lead dancer, main lead rapper; 6th youngest or 8th oldest
Ryeowook- lead vocal; 3rd youngest
Siwon- 4th youngest or 10th oldest (in reality is older than Donghae)
Eeteuk- Leader; oldest
*for some reason, Siwon has a stage birthday:1987, actually born in 1986 (still younger than Eunhyuk by days, but older than Donghae by a few months)
* Eeteuk, Yesung, Kangin, and Eunhyuk are all stage names (Shindong is also a stage name, but he used his real name to make it up, his first name is Donghee which is extremely similar to the member Donghae).
*there are support rappers: Heechul and Donghae and support dancers: Sungmin, Eeteuk, and (not often) Siwon. They are brought in when the leads have just performed, are not available, the supports themselves have their own parts, or (in case of choreography) "the central part" needs more people.
***Along with Super Junior are 4 sub-groups, to fill in when Super Junior is not promoting as a whole, SM wants to keep SJ in the entertainment scene (be it MC-ing, music, acting, or show appearances) at all times.
First sub-group-- Super Junior K.R.Y. (Kyuhyun, Ryeowook, Yesung): notably best 3 singers in the group. Their songs target a mature audience with R&B ballads. They only contributed to original soundtracks or collaboration soundtracks. Active in late 2006.
Second sub-group-- Super Junior T (T=Trot: Eeteuk, Heechul, Kangin, Shindong, Sungmin, Eunhyuk). Created to bring back the trot genre of Korean music among the younger generation. They successfully have done so with two digital singles. Active in early 2007. Remade their song: Rokkuko in Japanese in late 2008.
Third sub-group-- Super Junior Happy (no abbv.; consists of every member of SJ-T, except Heechul is replaced by Yesung) Intended to bring a happy feeling to the audience, hence their name. Their songs are cute and catchy. Released a mini-album, active in 2008 to balance out SJ-M, who promoted in China.
Fourth sub-group-- Super Junior M (M=Mandarin; Hankyung, Siwon, Donghae, Ryeowook, Kyuhyun, and two new members not in SuJu's original line-up: Zhou Mi and Henry) Although they were announced before SJ-Happy; they debuted afterwards. SM Ent.'s most controversial group. Henry was considered as a 14th member of Super Junior, causing major riot of "only 13" fans and dislike the formation of SJ-M and not to mention Zhou MI and Henry themselves. SJ-M's target was to bring the K-pop wave to China. They promoted from early 2008 to early 2009, releasing a full studio album (Me) with Chinese remakes of their most popular songs and brand new, original songs. They are expected to release a second album later this year.
*As of 2008, all Super Junior members have been in at least one-sub group, except for Kibum, who took the time off to film his drama.
*Each sub-group has finished their debut promotions, but all sub-groups are expected to make a comeback.
*Kibum has not comeback ever since SuJu has finished 2nd album promotions. He's is currently taking time off for acting, and he recently got injured, too, so he was M.I.A. for SuJu's 2nd Asia Tour, which just kicked off.
It's a lot, but it only took me an hour to learn all names :)