Many times people will have some ideas of what they would like to accomplish with their website. If you have no idea try taking some time to surf the web. Look at the sites of businesses or organizations similar to your own. Think about who will be visiting your site, how you think they may find you and what sorts of things they will expect to see.
If you are interested in learning more about web design and development this is a great place to start:
Tutorials from W3C (the web standards people)
If you already are doing web design and don't have the Firefox web developer's tool bar you should get it, it's an awesome tool!
Web developer toolbar for Firefox
Do you rely on people finding your site by searching Google? Who better to consult with on the subject than Google themselves:
Search Engine Optimization according to Google
The first thing you will need to have your own website is someone to host it. Web hosts provide space on their server for you to store and display the information that you want to be seen on the internet. You will also need a domain name, also known as a url or website address. There are many options for finding a host and domain name. I would be happy to help with this process or you can do this yourself. If you live in the Corvallis area some local options include Peak and Exchangenet. Or just do a search for web hosting and you will get many results.
For businesses the best option is one of the many paid web hosting services available. These services can run from just a few dollars per month and it goes up from there depending on what you need. For most business uses you can find options with lots of great features for $10 a month or less.
These sites are good for personal use, or for a small organization on a tight budget. Free sites have their quirks and I wouldn't recommend them for businesses. Sometimes networking sites such as myspace or facebook can be used as a supplement to a site and a way to provide more incoming links.
Providing the written content for you site is one of the few things I can't help you with. Not having content ready and organized can hold up any website. Think about what items you will have on your navigation/menu (the words or images that will link to the other pages in your site.) Write up a document in either Word or a text editor with the written content for each page. Try to make it clear what content goes with each page and what menu item from the home page will lead to it.
Once your site is designed you need to think about how often changes will need to be made and how that will happen. If you are technically inclined this may be something you can do yourself or I can do updates and redesigns for you. The other option that I have been working on lately is the idea of Content Management sites. With this type of site you can log into the site and make changes yourself using an editor. I am currently doing a redesign for a client and I am using Wordpress to allow them to do this. I wil be posting more about this option as I complete their site.