A college level (local community college is fine) Biology I class could really help you out. And do a lot of reading. This is a good book (old, but the information is still relevant): https://www.amazon.com/Thread-Life-Introduction-Molecular-Biology/dp/0674887557
Take your time reading it. There's some fairly technical information along the way, but I think it still stands up.
You should read
Seeds of Deception and Genetic Roulette both written by Jeffrey M. Smith who backs his writing up with hard scientific facts.
http://grist.org/series/panic-free-gmos/
It is a series of articles about GMOs written by Nathanael Johnson. It is really well researched and written.
Also, this book: Tomorrows Table, by Pamela Ronald and R. W. Adamchak. It is written by a GMO researcher and an organic farmer who are married. Written with a lot of good citations, and very accessible to a lay person. Link: http://www.amazon.com/Tomorrows-Table-Organic-Farming-Genetics/dp/0195393570/ref=sr_1_sc_1?ie=UTF8&qid=1408658213&sr=8-1-spell&keywords=tomorrow%27s+tabe
Well done taking the first steps to educate yourself!