Hi and welcome to Tech Soup
A quick google search turned up
http://www.resourcemate.com/
Which seems to be a scalable solution and offers some nice options.
Where I use to work we had a saying about our order entry process when they computerized it.
"We have taken a dysfunctional process and electrified it."
Meaning, don't assume a computer system will solve any problems. In fact it will amplify problems and bring about more frustration if there are underlying issues in your process.
The Dewey decimal system has been around and used successfully for over 200 years in libraries. But with either a computerized system or Dewey, if the books are not filed in the correct place on the shelf, they still will not be found.
If people are lax in properly checking out the resources, if on paper or through a computer, you still will not be able to track and report on locations.
I'm not trying to be a downer on computer automation, but trying to be realistic in what computerizing your library could do for you.
Dave