A good textbook on GMO
I too had difficulty finding any textbooks or notes that focused solely on genetic engineering. However, after some rather intense looking, I did come across several textbooks that may be helpful. I wasn't sure how basic of a text you were looking for but I'm hoping college level is okay because that is all I have been able to find.

The first book was An Introduction to Genetic Engineering by Dr. Desmond S.T. Nicholl. 

Another was Principals of Gene Manipulation and Genomics by Sandy B. Primrose.

If you need a more basic biology text for reference, I would recommend Miller &amp; Levine Biology by Prentice Hall (Pearson Prentice Hall). Also, you could do a quick-study on genetics on Khan Academy - Crash Course: Biology and Ecology.

I hope this information was helpful for you!