UX Booth is one of those sites that has really good resource articles. I visit this site often when I'm looking for information to help improve the usability of our websites at FHU.
One such article that I found is entitled "Creating a Usable Contact Form". Many of the items in this article can be translated to any type of form.
There are some very simple things that you can do for your online forms to make them very usable and to help bridge the gap between your users that are very tech savvy and those who are not.
Some of the important, yet most overlooked areas of form design are discussed in this article: failing gracefully and providing an alternative to the form.
It is important to consider several different user roles, computing environments and levels of communication when developing web forms.
You have to keep in mind, these forms are the way that your users are communicating with you. Good communication is two-way. Poor communication frustrates those involved.
For forms that you've seen or used online, what did you like most about them? What seemed to work well?
What didn't seem to work so well? Please share.