The Essentials

The American Association of Veterinary Medicine (AVMA): This site has everything you want to know about a career in veterinary medicine.  Here you can find  information on current  issues in the field, salaries of  first year vets  fresh out of vet school, and  much more. You can also access the Journal of the American Veterinary Medical Association (JAVMA).

Veterinary Medical College Application Service (VMCAS): When you apply to vet school, this is the site you'll need.  It contains the common application used by most accredited vet schools. 

Association of American Veterinary Medical Colleges (AAVMC): The AAVMC oversees the VMCAS site.  This site also has a lot of information on different opportunities available to prevet and vet students.

ETS : Before you apply to vet school you will need to take the GREs, a college-level version of the SATs.  This site will tell you everything you need to know about the exam, as well as how to register for it once you're ready to take it.

Veterinary Medical School Admissions Requirements (VMSAR): This is a book published by the AAVMC that provides a description of every AVMA-accredited vet school, including information on requirements and admission rates.  A new edition is released every year, so it's a good a idea to wait until the year you apply to purchase one.

Internships and Opportunities  

UVM ASCI Dept. Internship & Careers Page: Here you'll find a pretty extensive collection of  internships and careers from all over the world organized by concentration. Many of the internships have been done by other UVM students and have testamonials about their experiences.  Keep in mind that if you are an ASCI major you may be able to get credit for an internship that you do. You can find information about how to go about doing that here as well.

Cooperative for the Real Education in Agricultural Management (CREAM):  CREAM is a two semester, 8 credit course at UVM during which 15-16 students learn to milk and make management decisions  for a 34 lactating cow dairy farm.  No matter what level of experience you have with cows, CREAM is a great way to learn about the dairy industry, make connections, and gain valuable leadership and time-management skills.  Talk to your advisor or previous CREAMers to see if it's right for you.

EQUUS:  This is a UVM course in which students gain hands-on experience riding and working with horses as well as learning how to make management decisions about horses and horse barns. It's a great way to gain experience with horses if you've never worked with them before. You can choose to do one or two semesters. As with CREAM, talk to your advisor or those that have taken EQUUS before to see what it's all about.

Advice

The Student Doctor Network: You can find forums for any type of medical student at this site, but the veterinary forums are the most relevent. Here pre-vet and vet students can ask questions and other students or veterinarians answer them.  You can also find the inside scoop on vet schools from students currently going there.  There's some great info here if you have the time to peruse it.

"Myths Surrounding Admission to the Study of Veterinary Medicine": This is a page from the University of Illinois College of Veterinary Medicine that talks about some common misconceptions about applying to vet school and being a vet.

Alternatives to Veterinary Medicine: You may find that veterinary medicine is not for you somewhere in your undergraduate career, but no fear! The same courses and experiences that you undertook as a pre-vet student are very applicable to other fields. This page contains a list of other possibilities.  It is tailored after animal science majors so it is not a complete list of things you could do.  

Several vet schools have pages providing great tips on how to be a successful applicant.  They include The Ohio State,  University of California-Davis and Washington State University,  

For Fun

The Merck Veterinary Manual: This a go-to guide on many of the diseases and ailments you may run into as a vet, including the  etiology, clinical findings, diagnoses, and the treatments for them.  In other words, the veterinary bible.

U Penn Computer Aided Learning: This site outlines how to give physicals to a variety of large animals, as well as restraint techniques, vaccination techniques and a wealth of other information.