Delia's book is very basic indeed. Someone bought it for me when I was a student. It's got some good recipes for cake, a nice roast lamb with a rosemary & onion sauce, but mostly it's about how to boil an egg and mash potatoes.
I can cook pretty well but still refer to Saint Delia (as she's known in our house) regularly. The how to cook book is good because it shows you the basics and then some more impressive recipes too eg everlasting lemon curd souffles = LOVELY