Here are some good links to companies that sell composites, and also have freely downloadable examples, video clips, and tutorials:
http://www.fibreglast.com
http://www.acp-composites.com/
http://www.cstsales.com/articles_for_model_builders.htm
I recommend browsing these sources first, since they've all been in the business for a long time, and are quite helpful. Here on RCU, opinions vary widely about what resin to use, what fabrics to use, what fillers to use, and all the details of the many composite methods available. The web sites above have the serious technical information you need as a "primer".
I also have several composite-related tutorials on how to make plugs and molds on my non-commercial web site, at
http://www.nextcraft.com