There are a couple of ways to keep up with new releases in The Scinegue Series. The 'About the Author' page on Amazon has a simple area to click on the right side of the page under Stay up to Date.
You can also email me at firstname.lastname@example.org and ask me to send you an email when a new book is released. No spam involved, don't worry. Just a short email letting you know when the next book is available for purchase. I like to release my new books at a discounted price as a thank you to everyone who is reading the series but I only keep the price discounted for a couple of days so using Amazon's service or asking me to email an update is probably the simplest way to catch the book while it is on sale.
Update: The third book in The Scinegue Series is with the editor now. That means a new release should be out within a month! (Edited April 20: See http://srbooth.blogspot.com/2014/03/dont-give-release-date-until-youre.html lol!)