Building a technical library

Looking to develop a technical library for about 15 staff members all under the same roof. Subject matter would focus around Juniper/Junos, TCP/IP, dwdm, python, java, and expand from there. The O'reilly Safari service looks rather comprehensive, although at $400/user there may be more value buying hard copies and own them outright (or at least until they walk away). Are there other online resources that offer a good value? Other experiences weighing the pros and cons? Thanks, Chris