Is there anyway on the dd-wrt to check to see how much bandwidth each client is using? I ask because I am in charge of looking over a group of routers connecting to a dd-wrt router and if a user is using too much at certain times I would like to be able to see that, and i am not all that familiar with dd-wrt.
Assuming you want a bit of long term visibility to diagnose who is using a lot of bandwidth over time, DD-WRT has this cool feature called rFlow which can send data to a remote server that collects it. The server choice is up to you, but I'm personnally a big fan of nTop.
This blog post raves about the amount of visibility this can give you. Let me know if this is not what you were asking for.
Install a shibby version of Tomato (I said Tomato because generally Tomato is compatible with DD WRT devices); it allows you to monitor IP traffic based on IP addresses and hostnames.