Commissioning a museum computer exhibit can be a confusing business. This page has links to documents written by a range of experts. At the moment a lot of this advice is from people I know. But if you know of some other good advice on the web let me know and I'll add a link.
Information from the Scottish Museums Council. Well written and useful. If you don't do anything else then read the recommendations on page 7 of the summary report. Although designed for web projects the advice is spookily similar to my documents about gallery exhibits - which is nice.
This is a huge resource aimed at those developing on line "collections style" web sites. There's lots of good stuff here but I found it all a bit unfocused - it doesn't really address why you would want to develop a site like this and why visitors would want to use it.