Using the resources listed here, you'll find information on the following:
Genetics Home Reference is a starting point for consumers interested in learning about human genetics and inherited disorders. Contents include: Condition Summaries, Gene Summaries, Gene Family Summaries, Chromosome Summaries, Handbook and Glossary.
The purpose of Medline Plus is to inform and educate the public about health-related issues. Topics range from health and prevention, vitamins and supplements, medical conditions, terminology, and more. Links to additional resources are provided. You may find some of the images, videos and tutorials useful for your presentations.
OMIM (Online Mendelian Inheritance in Man) may be the most technical, but it's still accessible to the general public, and updated the most frequently when compared with the other search tools listed here.
Gene Reviews is part of Gene Tests, and both are used to inform the public about genetic conditions and tests. Although Gene Reviews is geared for public consumption, you may find it slightly more technical than the Genetic Home Reference. It is also updated more frequently than the Genetic Home Reference. Search by disease or gene symbol and select the "GeneReviews" link to access information.