I met Valerie at Swanwick earlier this year and am flattered she wanted to share this post as she reviews some prestigious books on her website. If you want a well written review to guide you as to what you might read next, have a look at Valerie's website. There are also other posts sharing writing advice and so on.
As for guest blogging, it is a great way to support other writers and for them to support you. The other great way, of course, is to review books and stories though I know Amazon, for one, have tightened up the rules here. I can understand why (they want to make sure reviews are genuine) but obey the rules and you can still review.
There's also nothing to stop you reviewing on Goodreads, your own website etc etc. The great thing about helping other writers like this is it brings variety to your website and when your site is shared (and it will be, my experience has been most writers are very generous when sharing and are always keen to return the favour), others wiill discover what you write.
Guest blogging can, of course, also be good practice for future blog tours and the sharing of links helps all writers. I've come across many a great site because I've read a guest blog on a site and can see why that writer was invited to do so. I, of course, then go and investigate that guest writer's writing in more detail. So happy blogging - and guest blogging!