I've probably mentioned it before, but I love the book that this thread is named for -- How to Cook Everything by Mark Bittman. There's an app version now, actually -- I got it free from one of those Starbucks Pick of the Week cards but it only costs 5 bucks to buy. Which is a lot for an app, but a real bargain compared to the $20 hardcover version.
I have been using it a lot when I get something from the produce box that I'm not sure what to do with. It's nice because before each entry (which could be an ingredient, like kale, or a type of recipe, like cakes) there's a little description of that type of food and the important techniques involved in its preparation (how to butterfly a pork chop, how to cream butter). And for every recipe, there are simple variations on the basic technique that allow you to sub ingredients that you have on hand.
So you can look at the entry for something you have a lot of -- let's say you got boneless chicken breast on sale -- and page through the recipes to find something that sounds good (like sauteed chicken cutlets with wine sauce) and then look at the variations to see if you can make one of them with stuff you have around the house (sauteed chicken cutlets with: cream sauce, ginger and warm spices; lime sauce). And like Wombles noted, it gives you a good idea of what kinds of things work together and what doesn't.
I've found, by and large, that you can tell if things are going to taste good together by how good they smell together.