When I transferred schools I emailed the dean of Stanford medical school (yes I was a little precocious but I figured if he thought I was a wack or a loon it wouldn't matter because I knew that I would never have a prayer of getting into that school so the probability of our paths ever crossing prior to admission to med-school was essentially nil).
Anyhow, he was probably the kindest person I had ever talked to, in the email he gave me his phone number and we talked on the phone for roughly 30-40 min. He addressed all of my concerns and answered a lot of questions (and also killed a lot of myths) about medical school and the application process. By the time the conversation had ended I really was glad that I took the 'risk'.
Also, I made an appointment with the dean of admissions at the medical school where I went to for ugrad. We talked for, again, about 30-40 min. She went over my transcripts MCAT scores, extra curriculars, and offered some really solid advice about how I should approach the entire process. I was afraid she would say I didn't have a chance in Hell, but I think she saw my sincerity and passion for what I was doing and was really supportive.
The key is don't sound desperate (it will give off a bad vibe), secondly sound adamant about what you want, if you are wishy-washy (well, I want to be a physician but...) they can't offer you any solid advice until you project to them that this is what you are going to do with or without their advice. Also, and most importantly, be sincere and honest. If you aren't honest with them i.e. don't be afraid to disclose past failures, you will never fully benefit from their advice. You need to paint them a complete picture. I basically told them what my grades/scores were, my extracurriculars and absolutely stressed that I was willing to do whatever it took to get to medical school because that is what I knew I wanted to do.
Don't ever be afraid to ask for help or advice from the people that write the books on admissions...they are human too!!
-PlAnEjaNe