I havent read all the suggestions Dubfore, but hopefully some of these havent been mentioned already. First off, write a post in your CC area asking the members what they would like to see happen in the club. This could be seen as an easy way out, but it could work if you get enough members asking for the same thing.
Run a league system, with different divisions. Give the same amount of points for each league division, so the members in the lower divisions have just a good a chance of winning as those in the higher divisions.
Have a player of the year set up, where members receive points for the leagues, and any other big tournys you create. This could result in a player winning this, that hasnt won the league.
Try get somebody who is good at creating graphics top make up a few trophies to award to members, and place them on the members profile wall. Believe me, members like to see this type of stuff, and seeing them on their walls makes them want to win more.
I have seen 1 suggestion where they say dump those who dont participate, and i can only agree with that. A club full of members who arent playing will only stagnate things. When checking new members out, make sure they are fairly regular playing the game.
Set up a poker league for no money, and run it once or twice a week. Pokerstars is a decent enough site. This could be a winner if you have enough players who play poker.
If you have members who you think are more than willing to work with you, then by all means, let them. You could ask in a post on your cc wall if anybody would like to take on the challenge of creating tournys etc.
1 more, and maybe the hardest 1 to do. Ask members if they are willing to donate to prizes. Prizes are what members are looking for when they are newish to the game,and friendship comes later when they are settled and know you more.
If i think of any more, i will post here for you, and good luck with the club too.
Jimmy.