Grades are important but not everything (have a life too)... I have been told that 3.5 is a good target GPA to be competitive for residencies. Having good recommendations is huge so get to know your specialists early. Getting involved in research projects for the summers is a good way for them to get to know you, and research is always something that makes you stand out.
Don't narrow your focus before you even get in... it's difficult to know what you like before even knowing the medicine. I shadowed doctors at a referral center the summer between 2nd and 3rd years... spent time with oncology, cardiology and internal medicine because I thought I liked those specialties. They kicked me over to surgery on slow days... and now I am aiming for a surgery residency. So you never know what might interest you. One of my classmates was dead set on a small animal surgery residency since the first day of anatomy first year... and now he is an equine-tracker. Vet school is fun that way, you never know what you'll fall in love with!
