Information on new releases in series is taken from http://www.fictfact.com/BookReleaseCalendar which doesn't require an account to view. (I just added links to booklikes book pages where possible and some sample bookcovers)
On screenshot: "A" = no account needed to see all new releases in book series; "B" = narrowing results to just your series option does require you entering series you want to track/follow. If trying to find me on fictfact, I'm at http://www.fictfact.com/user/DONealRice .