How do you recommend I do it?

Hi,
I'm new to this forum, so: Hi, to everyone!

but here is my story:
I made a design for my website in The GIMP [a program like Photoshop], which is completely finished now
but now I was thinking: what would be the best way/program/software to make my website, from the design I made?
after a few minutes of thinking of where to ask this question, I got to this forum: the forum of a website which has the best graphical designers on it.
if you could help me out here, that would be great!

The main purpose of my website is using it as an online Portfolio for my designs [and other stuff].
I am running Windows XP, with all updates.

Here is the design for my website: [ofcourse, the real design is without the watermarks]
http://img153.imageshack.us/img153/3663/websitedesign3fq0.png

here is my question again:
what would be the best way/program/software to make my website, from the design I made?