Working the akismet queue is pretty straight-forward. It is helpful when every moderator checks the queue each time they stop by the forums. The more eyes on it, the less effort for each of us. :-)
To reach it, login and then click the "Admin" link next to your name. Click on "Manage" and then click on "Akismet Spam".
For each item in the queue you need to make some decisions. Is it clearly spam? (smuggled links, blatant ads, etc.). Check their profile and make sure none got through - If they are consistently spamming, feel free to post to the wp-forums list to get them bozo'd -Then click the "delete" link.
Not sure? Check the user's profile or the linked topic to see: a) Is this a valid new topic? b) Does this contribute to listed topic?
Sometimes you have to do both to catch dupes. Some folks panic when their new post doesn't show up and try again. and again. and again...
We encourage volunteers (that aren't mods) to use the modlook tag to mark questionable topics. If you use a news or feed reader it may be helpful to subscribe to the modlook tag feed at http://wordpress.org/support/rss/tags/modlook
If you don't use a feed reader, consider adding a bookmark to http://wordpress.org/tags/modlook instead.
If you use Firefox, adding the RSS feed to your browser as a Live Bookmark is a very handy way to check for new threads that need attention every so often.
If you do check a suspect topic tagged with 'modlook' and attend to the offending post/user, be sure to remove the tag from the thread.