These are my favorites--none are new, but very complete--should be easy to find on Amazon, Alibris, etc.
Know Your Serger (In my opinion, this is the best one) ornamental techniques and make gifts as you learn.
Sewing With Sergers ISBN 0935278 A must for learning how to use a serger.
Creative Serging 2nd book of above ISBN 0-935278-12-5
Serging Inspirations-Nancy Zieman. excellent leaflet
The Serger Idea Book ISBN 0-935278-18-4
fab ideas for sewing garments--I about wore this one out!
I have used a serger for 25 years--they were very pricey then, but it paid for itself many times over. I had a 4-H Horsemanship Club, and taught all the girls to sew on a sewing machine and the serger--we spent a whole summer and fall making their horse furnishings, show outfit, and school clothes.