if thats what you mean.

Generally, on my website, (http://sliceanddice.ucoz.com/) when someone posts something in the Guestbook, it goes unnoticed.

To change this, I want to make the link to the Guestbook in the site menu, change colour or flash/blink or do something that makes it more noticeable. Anything like this, even just "New Post" appearing next to it would be great.

Does anyone know how I would go about doing this?

Thanks

Are you sure though? Because in the Control Panel > Guestbook > Module Settings you get the option of sending a e-mail to the administrator when there is a new post. Could I not somehow get this code and change the action so instead of sending an email it will change the colour of the text?

Im extremely sure that this is not a feature thta is possible. Try asking for it in the next update...