Hello,
I'd have to agree with turtleboard. Unless you're at a school like Harvard, which offers a more research-intense track, most schools (MD or DO), will offer at-best cursory training in research methodology and design. The curriculum, in most cases, is simply too crowded. But, most MD schools will have opportunities to get involved with projects at any level. As far as DO schools are concerned, I am only familiar with my school, and a couple of the public DO schools (North Texas and Ohio). Each of which has strong basic and clinical departments with good NIH funded programs. At MSUCOM, faculty encourage student involvement in projects. Actually pursuing it, within the first 2 years, depends on your own level of interest and motivation.
Sudhir