There's a medical science article database called PubMed (
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi) that allows you to search dozens of medical journals. There are hundreds of articles on steroids, bodybuilding, and supplements. I've found many good articles here, and they might be of help to anyone looking for some scientific evidence to cut through the bull.
I think that you can read the abstracts for free, but if you want to read the articles, you need to either pay or access PubMed through a University library or other subscriber. The abtsracts are usually good enough, though.