For example, it never occurred to me and no recipe I'd seen at the time told me, that I should let my lasagne rest for a bit in order for the cheeses to set. So for the first several years I made it my lasagne was served immediately (I was impatient!) and each piece ran all over the plate. I didn't care that much but I wondered if I was using too much sauce or something!
I also didn't understand that the term confectioner's sugar meant powdered sugar, so for a few years I made a recipe called "simply wonderfuls" or "sweetballs" from ISKCON with granulated sugar and wondered why the texture just wasn't like those made in the Hare Krsna temples. (scratches head)
I didn't know until last year that tomatoes shouldn't be stored in the refrigerator. (I heard this on foodtv and it made sense when I thought about it.)
No one ever told me not to salt beans when cooking them from scratch, until they were done cooking. But somehow it worked for me anyway so while they might have cooked a bit faster, they got cooked in the end.
When I first made muffins no one told me about over mixing and why that makes them heavy and flat rather than light and fluffy. Finally I stumbled on a recipe that mentioned this.
The first few times I made corn on the cob, I had no idea how long to steam the corn. It seemed so firm, and coming from the land of the midwest where my family boiled vegetables to death, I went ahead and kept them steaming for a good 45 minutes.
In fact, since I was self taught and had only one cookbook for the longest time, I had many misses as a new cook and could really have used a guide. These days there are books out for new cooks to explain cooking terms and basic techniques, but I didn't know about anything like this when I started out. There are still things I've never made--souffles, for example.
So--what are some errors you made or things you found confusing? Or do you have questions about a term that either I or some of my cooking friends can help with? Would you like to suggest a title of a cookbook you found very user friendly?