I hate the word 'monetising' so I'm not using it, but that is what I am talking about.
The simplest way of earning a little extra money from your blog is to advertise Amazon. You have to set up an associates account, but once you've done that, it's easy as you just add their widgets to your page. Then, everytime someone (including yourself as far as I know) buys something via the link on your blog, you get commission.
On the left hand side of this page, you can see three links. The top one is for my kindle book which is a link to the amazon page. I created that one by using the 'picture' gadget and providing a link to the Amazon page. This one DOESN'T get me any commission, but as it leads to a sale I'm not too worried.
The other two are a 'carousel' and 'then picture cloud' which are available from the associates page. Amazon build them for you, all you have to do is select the books for the carousel and in the case of the cloud, the widget will base its recommendations on your choice of category (books - what else) and the frequency of the words on your blog.
What could be simpler?
It's unlikely to provide you with a mass amount of income, but as they say, every little helps.