So here it goes in 5 steps.
1. Create the document (this you may already conquer!!, one down and four to go). Sample is a presentation.
2. Change the privacy settings of your document to make it "Anyone with the link"
3. Go into the right corner to Share - Publish/embed
4. Click on Publish Presentation
5. Copy and paste the code into your blog.
If the instructions are too hard for you, take a look at the presentation bellow.
That is all, hope it helps.