I am just restarting to use RSD. I am trying to rebuild only because I was warned by 'google' that my being seen on Google would become less unless I went 'responsive'.
I will attach what I have done today. My org. site is www.printplus.co.za , done in Dreamweaver years ago, where you can see what I am trying to do.
My big puzzle here is how to get the "ad" Quality printing up into the top corner as it is on my present site. www.printplus.co.za. That right colum should almost be its own - as it is just for ads on the side of the site. Thank you

I have thrown together a small layout for you. Try it. You get a right sidebar by making one row with two columns, the right column the width of your intended adverts. In the left column you drop a subgrid, which you can extend downwards with as many rows/columns as you need.

I have also made the suggested layout somewhat wider, as most people now have much larger screens than 800px.

BTW, check your Quality Printing advert for a typo ("grahics").

No. I hadn't till now. Thank you so much for your efforts. That helps a lot. I will now read up on sub grids. I had a feeling it was something like a container within a container - but not! Thanks again. The spelling -- Embarrassing - must have been there for more than 10 years!!!