I think I read some where that you should collect your transcripts yourself and send them all in together. Is that true?
I don't think there's necessarily a "should" there... I believe that most schools expect that the transcript will be mailed directly from the issuing institution. Some obviously require direct mailing (given BostonLvr's post), but I know for a fact that some don't mind if it's been through your hands, so long as it's in a sealed envelope signed across the seal by the registrar of the issuing institution (most institutions seem to offer the option of having an official transcript sent to yourself in a sealed/signed envelope). I know because I had a couple undergrad transcripts left over from when I applied to grad school, and I sent them to some of the vet schools I applied to instead of ordering all new ones.
The one case where it might be better to amass transcripts yourself (provided it's allowed by the schools you're applying to) is if you have a *lot* of them. Each institution has slightly different policies about how you request your official transcript (online, by mail, in person) and how long it takes them to "process" your request. Several people on various threads have reported problems with an institution not sending out a transcript, or sending it to the wrong place, or something along those lines. So if you've got transcripts from X different institutions (CC, undergrad, transfer, postbacc, grad, whatever), and you're applying to Y vet schools, you could have Y sealed copies of your official transcript sent to you from all X institutions, collate them into Y different packages and send one off to each vet school. And request delivery confirmation on your packages. That way you'll know that each vet school got all X transcripts. To do this, though, you've got to make sure you request all the transcripts early enough to have them sent to you and for you to send them back out again by the deadline (which may be different for each school).
Edit: If you go the above route, I don't think you necessarily need to call the admissions office to give them a heads up when you send the package, but you should enclose a polite cover letter with your full name *and* your VMCAS application number so that they have the best possible chance of being filed correctly. Despite doing exactly that with one of the transcripts I sent myself, I later got an e-mail from that school saying my app was incomplete. I replied back with the delivery confirmation tracking number, which showed that the letter had been received by their office two days after I sent it. They wrote back and said "sorry, we found it, we'd filed it in the wrong place." So even sending transcripts yourself is not foolproof...