I decided to use Flickr for my online portfolio since I’m just using it for fun to share my pictures, and Flickr is easy to use, easy to share with friends and free. Those 3 factors mean that I will actually use it, which I think is the most important thing.
I’ve added some photos to my account and will continue to add more over time.
Another item would be to update your profile with contact information / website etc. Almost every day someone contacts me who wants to pay me to use some of my photographs for something. They do this buy going to my profile page: http://www.flickr.com/people/thelastminute
Also you should pick your licensing. I choose creative commons Attribution, Noncommercial license. That way people can use my images for their creative projects etc…
I like that each photo has descriptions but also remember to to tag them. The more metadata you can associate with your images the more searchable they are…
Finally, be cautious about investing too much time into flickr. The service is dying a slow death at the hands of yahoo. I would predict that in a five or ten years it will be gone. But until this it’s a very viable platform for photosharing.
Another option if you get more serious is that you may want to control your own domain or use one of the newer photosharing services like photoshelther.com