I’d recommend Marguerite Patten’s book “Basic Jams, Preserves and Chutneys”, available from all good bookstores
I’d also recommend a jam thermometer, takes some of the guesswork out of the process, although I still also use the “wrinkle test”. If you want a slightly offbeat taste, use soft brown sugar instead of granulated, it gives a richer, darker flavour.
You could also try using lemons, limes or grapefruit as well as the oranges, it gives a fuller flavour.
It’s taken me a good few batches to get the hang of it, suggest that you experiment and find a recipe that works for you and which you like the taste of
Happy cooking!