Help with how to theme a menu?

Hi

Im fairly new to drupal and css etc. I read on the jquery module page:

"Jquery menu is easily themable. Since the jquery menu blocks only use a small number of styles, and don’t use the default list styles, overriding it with your own css is easy. Also the important display elements are contained in themable functions so you can tinker with the layout if you like."

Being new to all this, can anyone please tell me how i might colour the text in a specific menu? Im using Advanced Taxonomy Blocks and JqueryMenu and would like to add different colours to the text on different levels ie:

Drink - would be the same as the site - grey / mouseover blue underlined
- Alcoholic - would be green mouseover lighter green maybe
-- Martini - would be red mouseover say orange
-- Becks beer - would be red mouseover say orange
- Non Alcoholic - would be green mouseover lighter green maybe
-- Orange Juice - would be red mouseover say orange
-- Coke - would be red mouseover say orange

I know than many of these stlye issues are from the main site theme css, but i am unsure how to go about adding such stuff and where to add it? I am aware you are a busy guy aaron and dont do this stuff so wonder if anyone else might be able to give me the basics of how and where.

Thanks in advance!