Here is a list of some highly recognized professional organizations. Many of these organizations have membership programs that can benefit you.

In Computing
ACM (Association for Computing Machinery)
Website: http://www.acm.org/

IEEE (Institute of Electrical and Electronics Engineers)
Website: http://ieee.org/

IEEE Computing Society
Website: http://computer.org/

In Information Systems
AIS (Association for Information Systems)
Website: http://www.aisnet.org/

SIM (Society of Information Management)
Website: http://www.simnet.org/

In Project Management
PMI (Project Management Institute)
Website: http://pmi.org/

In Security
ISSA (Information Systems Security Association)
Website: http://issa.org/

In Software
SAO (Software Association of Oregon)
Website: http://sao.org/

Here is a list of some links that can help you find internships. These internships could be the start of a great career.

SBA Career Services
Website: http://www.careersrvs.sba.pdx.edu/

PSU Career Center
Website: http://www.pdx.edu/careers/

MECOP (Multiple Engineering Cooperative Program)
Website: http://mecop.orst.edu/apps/apps.html

Experience
Website: http://www.experience.com/

The Princeton Review
Website: http://www.princetonreview.com/

InternJobs.com
Website: http://www.Internjobs.com/

INROADS
Website: http://www.inroads.org/

Intel Internships
Website: http://www.intel.com/jobs/usa/students/internships/

IBM Internships
Website: http://www-03.ibm.com/employment/us/un_coop_intern.shtml

Microsoft Internships
Website: http://www.microsoft.com/college/ip_overview.mspx

Google Internships
Website: http://www.google.com/support/jobs/intern