I promise I haven't been holding out because I want to, I just feel EXTREMELY unsure of being able to explain things like this to anyone else when I've only learned through trial and error myself. I also have no idea what your tech background knowledge is and I may have lost you at the word embed, but here goes the short version...
I checked out a variety of techy web sites and I'm sharing what was easiest for me.
1. Start a new post. Click the Edit HTML tab above and right of where you are typing your blog post. Click on the following link to go to Copy Paste Code and copy and paste the HTML code where you want your file to appear in your post. If you are asked for a password, it is kindergarten.
2. Replace the words 'PASTE YOUR CODE HERE' with the unique URL of your Google Doc. (I usually have two browser pages up at a time when doing this so I can copy and paste from one place to another.) You have to be sure that your document sharing is set to: Public on the web - Anyone on the internet can find and view. See the picture below.
4. Set the parameters such as width, length and frame border to best suit the size of your page. I had to decrease the width because documents were wider than my blog posts. To do this, just click on the Edit HTML tab and change the numbers according to your preferences. (Ex. width: 550px can be changed to 500px or whatever number works for you)
If everything is right, you are ready to publish your post!
***Please feel free to comment or use the Contact Me tab at the top of my blog if you know of an easier way to do this. I use to be able to get the embed code directly from Google Docs, but I can't get it anymore, even through the old version.