On this site I have read about turning old sod upside down then covering with several layers of newsprint, then organic matter, then new top soil before establishing a new flower bed. If I intend to dispose of the old sod entirely, would it be prudent to still lay down newsprint, organic matter, and new top soil? I live in Riverdale, Toronto, north facing front lawn, clay conditions. Thanks.
Turning sod upside down, then covering with layers of newsprint and organic matter is one of the best ways of establishing a new bed, but it does take time. If you prefer to dispose of the old sod, you could remove it, dispense with the newsprint, add topsoil and organic matter and begin to plant. One caveat is that you will likely find that weed seeds that have been disturbed in your removal of the sod will begin to germinate, so that your new flower bed may not be weed-free. Adding new topsoil may well be a necessity: you may lose much of your layer of topsoil as you remove the sod, along with other important organic material.
The Toronto Master Gardeners, along with the City of Toronto, has produced a useful fact sheet on adding organic material to soil, which is always a good thing, and will give a great start to your new flower bed: https://torontomastergardeners.ca/wp-content/uploads/2012/07/Improving-Your-Soil-Organically.pdf Keep in mind that, especially with clay soils, it is very helpful to add organic material every year. You might be interested in this Toronto Master Gardeners post which discusses this and includes several links with good information on making the most of your clay soil: https://www.torontomastergardeners.ca/askagardener/creating-flower-beds-from-scratch-in-clay-soil/ . And when it comes time to choose plants, Landscape Ontario offers a look at native plants that thrive in clay soils: https://landscapeontario.com/these-native-plants-love-clay