I don't have a lot for this list, but that's only because each website has a lot to offer. :P
Top Four Things That Make Your Life As A Reader/Book Blogger Easier:
The site that I read awesomely hilarious reviews of books (that usually includes accurate gifs). Definitely a site that I value the opinions of people I'm friends with or follow. I also posts my book reviews on here first instead of my blog because of reasons. :P
The site that I spent most of my babysitting money on buying books because of its great deals in the past. Unfortunately, Amazon has had less awesome sales and discounts for the past year or two, which is why I've stop ordering books from them lately, but it's also because I have no time and/or money to buy anymore books. I've also heard that Amazon is going to start taxing customers now... D:
This site helps keep all of my blog subscriptions in order by daily reminders in my email. I switched over to it once I heard that Google Reader was being shut down some time this year. It's very useful, although I haven't been keeping up with my subscriptions for the past few months, so there's a lot I have to sort through.
Who doesn't rely on Google? :P I use it to look up for more info after I'm done reading a book when I want to see if there's going to be a movie adaption for it or to see if there's going to be a sequel or something equally awesome.