jump-menus...search engine readable...fast loading

hi, i know this is a very basic question...but important.

if i am using drop-down or jump-menus and would like to do them in CSS as much as possible, and at the same time creating them in dreamweaver/fireworks.......would my html code still be read by the search engines. i am concerned that by using an image or css it may inhibit the search engines from reading it.

If this is not a problem can someone suggest a good, quick loading way to do this?

many thanks