Hi,
I am new here but read this post and thought i would just maybe put out my point of view which hopefully will be of help.
Firstly with a photography website you need to have a clean and simple design as others have already said basically the user needs to get around your site as easily as possible otherwise they wont stay long enough for you to showcase your photos. that means have your navigation at the top and make sure the page doesnt stretch to far.
i totally agree with a couple of other posts about the fact that your content is as important as your photos as the aim is to try and build your reputation as a photographer as well as the reputation of your images. therefore maybe try and create a blog or an area where you can express yourself a bit and explain about your photos.
One thing that i would recommend is to stay away from flash sites. Although they are sometimes nice looking they will seriously hinder you in the search engines meaning not many people will find you organically.
With regards to what you need to run a website heres a list:
1) web hosting - this is where you place the code for a website so that it can be placed on the internet (sorry if this is obvious just noticed that there were a few people asking about it). You want to get reliable hosting ie dont get free hosting otherwise it can mean your site might be down alot
2) a web designer or alternatively a software package to create your own website. the problem with a web designer is that it is costly to get a good site but you will get a good site. the problem with buying software to create it is time and the difficulites of creating it properly without knowing alot of code yourself.
3) buy a website built specifically for photographers online. this has its bonuses in the fact you can create it straight away and it will work plus its cheap. the only problem is you have to be careful as you may be limited by what functionality you can have. Without being seen to plug this myself. we have just (today) launched our own wizard tool to help photographers create your own website. you can have unlimited galleries, blog, contact us, guestbook, ecommerce to sell your photos and alot more. If you go to
http://www.onlinephotographers.net/mysite.aspx
Anyway sorry about the long post went of on a rant

. If anyone has any questions about this dont hesitate to PM me and i would be happy to help or just post here.
All the best
Andrew