Our library is total Linux. Ubuntu 6.06 Dapper Drake on the staff and public access computers and Debian Sarge on my web server.
It can be done.

The money that I saved by not purchasing microsoft stuff was wonderful. I ordered all my machines with no operating system and that saved money. After the first machine (learning experience) I now have the setup time - install Ubuntu, install updates to Ubuntu, install internet filters, install flash -- start to finish 3 hours. I can setup multiple machines at the same time because the procedure is the same for all.
It's great.
I have a background in computer science and that was very much in my favor. But I also found that the Ubuntu and Debian forums are full of people that are very friendly and VERY helpful. I was also fortunate to have the help of some gurus in Alabama. John and Anthony and Trevor. But it mostly came from me and having access to the forums.
I have looked in webjunction and did not find very much support regarding Linux. I hope that changes soon.