[quote=@Gareth]
I may sound dense, I'm willing to admit that, but I have to ask, how do I tag people?
[/quote]

Don't worry, I'm still vaguely new here, emphasis on vaguely. I just pick things like that up quickly. :)

Basically you have two options; first: at the bottom of posts notice the @Mention button? Click that and it'll drop whoever you want to tag/mention/ping/whatever the appropriate word is, into the 'New Reply" box. Always at the end of anything you've written. 
Second: in the little buttons across the top of the 'New Reply' box thingie, there is one with an @ symbol on it, click that and you'll get a one of these [color=9e0b0f][[/color] followed by this [color=9e0b0f]@Username][/color], only instead of 'Username' you insert the person whom you are trying to tag. :) 
Gotta make sure your spelling is right though, I've seen people try to tag me using Angle instead of Angel at the end, doesn't work.
Hope that was helpful, and not too long winded. :)

(Sorry I couldn't show you what it looks like, as it just turns into a tag.)