web scrapping in R and how to give pagination an how to find the Html Nodes for an element in a webpage

I am new to scrapping and I started it using RVEST package in R programming after watching a tutorial and a simple example which was given in a website and the link of the website is given below (http://ift.tt/2tg1PyF)

My question is how can we find the html node of a particular element for which we need to scrap

I tried for this website and its link is http://ift.tt/2wRtHIA

It has lot of products and if you select a category it has lot of sub category and first thing which i Want to try is to get all the Url (links) of that website and then after that I want to run all the url at once and get the data which I want.

In that also How to give pagination to move it to next page.

So my query is :

1) Is there any simple way to identify the html nodes of a webpage or How one can read the html nodes easily 2) There is any possibility to get all the url of that webpage at once or else we have to go by category wise. 3)In the webpage which I mentioned above has more sub categories how to get the all the products at once whether there is any possibility for that 4)how to give the pagination for this website 5)Can we get all the urls and can run at once for a particular webpage