Need help in getting image thumbnails on Blog homepage

I’ve successfully created a blog using wordpress, problem I’m facing is that I want to post an infographic on my blog and what I want to do is that the thumbnail of the infographic should be displayed on the blog homepage and when someone clicks on that image of blog heading to go to that particular blog page he should be able to see the complete infographic which is 600 x 1300 size. Please advice how can I do that?