Software

This is a consumer product.
Don't expect it to do very much content filtering.

If you really want to control what your people is doing, then you'd need to put a proxy between them and the router (i.e. block access to internet for everyone except the proxy). Have a look at UNTANGLE, for instance.

A softer solution could be opendns.com
Someone, who knows their ins and outs, can rather easily get around such a "politically crippled dns server", but it may be enough, depending on your situation.

You could also think of rolling out some kind of web-filter to each work station, but before doing that, make sure you'll be able to handle the maintenance of such a solution.

Use Access Restrictions. All the info you need is available there, or at the support site.
http://homesupport.cisco.com/en-us/wireless/lbc/WAG54G

Or use a service like OpenDNS.