Without parroting what everyone else has said, I would get out and do some stalking prior to taking the DSC1 course. I think the information in it is far more useful and you will enjoy it more if you have some practical experience in which to relate it to. I did the DSC1, enjoyed it and go a lot out of it and had approx. 5-10 outings completed before I attended.
Before going out stalking you may want to attend a shooting school with a rifle range first (you may already proficient and so can ignore this). You want to make sure you already have the basics of fire arm safety and how to fire a rifle with a competent degree of accuracy. If you are a novice, I am sure the stalker will run through the safety elements prior to setting off anyway, but from your own confidence and a deer welfare point of view I would say its worth getting at least one trip to the range under your belt before going out.
No idea where you are based but I live in West London and can recomend the below shooting school from experience as a starting off point:
www.shootingschool.co.uk