Setting up a portfolio is very easy. You just need to be selective. People think that its a technical stuff.. but with wordpress it is much more easier. Just follow these steps and you can create your portfolio in just 5 steps.
An example of portfolio website is http://www.cssjockey.com
Get webspace and book a domain
Having a personal webspace and domain is very important. Its just about branding. Brand yourself, Branding yourself is the best thing to promote yourself.
WordPress is the one of the best open source publishing platform. Its simple and easy to manage and easy to post and publish. The best thing is that it have a lot of free features available. With lot of free plugins and themes, it is easy to manage wordpress.
Install a Free theme
There are lot of free themes available, these themes can be used to create your personal portfolio, that can be used to display your work easily.
Some of the sample wordpress themes are here
Upload your work.
Upload your work, if you are a photographer, you can upload your photos to flickr and display them in wordpress, this helps you save the space. You can upload your videos to any other website and embed them in wordpress.