CSS help

Hello. I am using the theme Witcher World (http://wordpress.org/extend/themes/witcher-world).

Can someone tell me how to change the CSS so that a) the hyperlinks on a post or page will be underlined and b) the hyperlinks in sidebar 1 will be underlined.

I really have very limited experience with CSS besides tweaking a few lines here and there.

Thank you for any help you can offer.

Taneya
[ email redacted ]