won't start

What is your question?

Over the past several weeks, when I turn the key to start my car it doesn't always start. When I try a second or third time it starts fine. This was happening intermittently and I wondered if I just turned the key to quickly or possibly didn't have the key inserted fully. Now it won't start at all, even after 100 trys! No noise or anything. I am hoping it is a fuse and not the starter. I replaced the battery about 3 months ago, so that is not the prob. plus lights are fine. Help! If it is a fuse, which is the one I change?