There are probably other threads like this, but I thought I would list a few of the free resources I've found that deal with season extension and cater to "beginners". I am sure all of most of you are familiar with Elliot Coleman's books (and other authors) but I wasn't going to list them. If any of you have other links, please feel free to list them.

ATTRA "Season Extension Techniques for Market Gardeners"

https://attra.ncat.org/attra-pub-summaries/?pub=366 (you can apply the same principals to a home garden)

ATTRA "Sustainable Season Extension: Considerations for Design"

https://attra.ncat.org/attra-pub-summaries/?pub=370 (this one isn't free but doesn't cost a lot)

UT Institute of Agriculture: The Tennessee Vegetable Garden: Season Extension Methods

https://extension.tennessee.edu/MasterGardener/Documents/W346-F.pdf

https://www.motherearthnews.com/organic-gardening/garden-know-how-extend-growing-season-zmaz07fmzsel

https://www.motherearthnews.com/organic-gardening/gardening-techniques/year-round-gardening-zm0z15aszsto

It's a little late to be thinking about season extension now, since Fall is fully upon us and winter is just around the corner, but maybe it will give you some ideas for next year.