Bleeping Blurbs

Let's talk about blurbs today, shall we?  Not really the type you'd need to bleep out, however depending on the book, some might need that.

I'm talking about those couple of lines on the back of a book that makes a reader go from, "Hmmmm, nice cover."  to "OMG-I must buy and devour this book!"

Now, yes, the majority of my sales for the series coming out this year will most likely be ebook, so no one will be physically picking up the book in a bookstore and pondering the back copy.  But back copy still needs to exist.

First reason, even though most sales will be ebook, I will be making print available for folks to buy should they prefer, so gotta have something there filling up that back page. Second, even for ebooks, a blurb is handy on the web-site, shopping site, swag, etc.

So, I'm going to need blurbs.  The first one shouldn't be too hard, it's mostly there already from previous query letters.  But the second and the third ones?  How do you blurb a book in a series where people who come across said blurb may or may not have read the first book?

Aka- how does one avoid spoilers? (BTW for you Dr. Who fans, I am hearing River Song saying "Spoilers sweetie!" right now in my head.) This issue is compounded by the short turn around time planned for the three books, there's not that year of dilly dallying about like there would be with a traditional publisher.

I'm starting to prowl through favorite series and reading the book blurbs to see how to keep things secret, but still entice a reader. But it's not easy so far.  Many of the blurbs honestly do give too much away from the previous books.

So today I'm asking any of you--got any blurb writing hints?  Have any books whose blurbs just knocked you off your feet?

Help me get past the bleeping part of blurb writing!