Urgent Dreamweaver Help required!

Hi guys.
I’m not bad at using dreamweaver in design view but alot of the html behind it is above me. CSS is something I’m still gettin to grips with…anyway to cut a long story short. I have numerous links on my website, 5 which make up the main nav menu, and others throughout the site that link to maps, other websites etc.

My problem is this:

I only know how to set the link properties i.e a:active, a:hoover, a:visited etc using the page properties button, as you will know this sets these properties for every link created within the site… still with me?

What I want is to have different links having diffenrent properties, as in my nav menu links looking different (different hover properties etc) to the links to external sites etc…I reckon its probably something to with attaching a differnt style to that particular piece of link text (or perhaps a behaviour rollerover or something!)but everytime I change the properties in my list of styles it changes the whole site.

I hope this makes sense…the simplier the advice the better i’m not good with css!!!

Cheers guys.