Hi! Thought I'd give you some thoughts...
The site has gorgeous pictures Good job! They are so clear and professional. I'd have to agree that the site is dated. First of all you are using frames which is not a good thing anymore. Converting it over to
CSS/
XHTML would be the best way to go.
If you aren't ready to delve into that, then I would suggest, changing the colors first. Butterflies are all colors but when you think of them you think of beauty, bright, happy colors. Your logo on the content pages has blue and yellow in it so I would go with very light pastels in blues and yellows. Maybe you could do a mid tone of another blue or yellow for contrast. Or the entrance page has yellow and red. Both good options on white or cream.
I would also simplify to navigation. All that repeating of the pattern on the buttons is sort of busy. I think I would try cutting out your favorite butterfly photo and using it as a bullet or as part of a rollover. Or something simpler.
I would also do away with the entrance page. All is does is make the visitor have to do an extra click. Everything in the main pages are well organized so it makes the entrance page unnecessary in my opion.
Check out
csszengarden for some serious inspiration...